Terminal, radio communication method, and base station

Abstract

To improve communication quality / throughput.SOLUTION: A terminal according to an aspect of the present disclosure has: a receiving section that receives a cell switching command triggering conditional L1 / L2 triggered mobility (CLTM); and a control section that controls the CLTM on the basis of the cell switching command. The control section acquires timing advance (TA) for a target cell by using a specific method before triggering the CLTM.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to a terminal, a wireless communication method, and a base station in a next-generation mobile communication system. [Background technology]

[0002] In Universal Mobile Telecommunications System (UMTS) networks, Long Term Evolution (LTE) has been specified with the aim of achieving higher data rates and lower latency (Non-Patent Document 1). Also, LTE-Advanced (3GPP Rel. 10-14) has been specified with the aim of achieving higher capacity and more advanced features than LTE (Third Generation Partnership Project (3GPP (registered trademark)) Release (Rel.) 8, 9).

[0003] Successor systems to LTE (e.g., 5th generation mobile communication system (5G), 5G+ (plus), 6th generation mobile communication system (6G), New Radio (NR), 3GPP Rel. 15 or later) are also being considered. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)”, April 2010 Summary of the Invention [Problem to be solved by the invention]

[0005] In future wireless communication systems (e.g., NR, Rel. 19 and later), support for conditional LTM (CLTM) is being considered as a mobility use case.

[0006] In CLTM, the same specifications as those of LTM in Rel. 18 can be defined for both RACH-less LTM and RACH-based LTM.

[0007] Here, for example, when RACH-less LTM is performed for CLTM, the UE needs to acquire the timing advance (TA) for the target cell before triggering CLTM.

[0008] Therefore, it is necessary to clarify how a UE obtains a TA for a target cell and the related provisions for this method.

[0009] If these points are not clear, it may not be possible to achieve lower latency communications, which may hinder improvements in communication quality / throughput.

[0010] Therefore, one object of the present disclosure is to provide a terminal, a wireless communication method, and a base station that can improve communication quality / throughput. [Means for solving the problem]

[0011] A terminal according to one embodiment of the present disclosure includes a receiving unit that receives a cell switch command that triggers conditional L1 / L2 triggered mobility (CLTM), and a control unit that controls the CLTM based on the cell switch command, and the control unit obtains a timing advance (TA) for a target cell by a specific method before triggering the CLTM. [Effects of the Invention]

[0012] According to one aspect of the present disclosure, communication quality / throughput can be improved. [Brief explanation of the drawings]

[0013] [Figure 1] Fig. 1A is a diagram showing an example of UE movement in Rel. 17. Fig. 1B is a diagram showing an example of UE movement in Rel. 18. [Figure 2] FIG. 2 is a diagram showing an example of the procedure for Rel. 18 LTM (R18 LTM). [Figure 3] FIG. 3 is a diagram showing a first example of conditional LTM operation. [Figure 4] FIG. 4 is a diagram showing a second example of conditional LTM operation. [Figure 5] FIG. 5 is a diagram illustrating an example of the operation of a target cell in conditional LTM. [Figure 6] FIG. 6 is a diagram showing a third example of conditional LTM operation. [Figure 7] FIG. 7 is a diagram showing a fourth example of conditional LTM operation. [Figure 8] FIG. 8 is a diagram showing a fifth example of conditional LTM operation. [Figure 9] FIG. 9 is a diagram illustrating an example of a TA acquisition method. [Figure 10] FIG. 10 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. [Figure 11] FIG. 11 is a diagram illustrating an example of the configuration of a base station according to an embodiment. [Figure 12] FIG. 12 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. [Figure 13] FIG. 13 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. [Figure 14] FIG. 14 is a diagram illustrating an example of a vehicle according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] (TCI, spatial relations, QCL) In NR, it is being considered to control the reception processing (e.g., at least one of reception, demapping, demodulation, and decoding) and transmission processing (e.g., at least one of transmission, mapping, precoding, modulation, and encoding) in the UE of at least one of a signal and a channel (referred to as signal / channel) based on the transmission configuration indication state (TCI state).

[0015] The TCI state may represent that which is applied to a downlink signal / channel, and the equivalent of the TCI state which is applied to an uplink signal / channel may be expressed as a spatial relation.

[0016] The TCI state is information about the quasi-co-location (QCL) of signals / channels, and may also be called spatial reception parameters, spatial relation information, etc. The TCI state may be configured in the UE for each channel or signal.

[0017] A QCL is an index that indicates the statistical properties of a signal / channel. For example, if a signal / channel has a QCL relationship with another signal / channel, it may mean that it can be assumed that at least one of the Doppler shift, Doppler spread, average delay, delay spread, and spatial parameter (e.g., spatial Rx parameter) is the same between these different signals / channels (i.e., they are QCLs with respect to at least one of these).

[0018] The spatial reception parameters may correspond to a reception beam (e.g., a reception analog beam) of the UE, and the beam may be determined based on a spatial QCL. A QCL (or at least one element of a QCL) in the present disclosure may be replaced with an sQCL (spatial QCL).

[0019] A plurality of types (QCL types) of QCLs may be defined. For example, four QCL types A and B may be provided, each having different parameters (or parameter sets) that can be assumed to be the same. The parameters (which may also be referred to as QCL parameters) are listed below: QCL Type A (QCL-A): Doppler shift, Doppler spread, mean delay and delay spread, QCL Type B (QCL-B): Doppler shift and Doppler spread, QCL Type C (QCL-C): Doppler shift and mean delay, · QCL Type D (QCL-D): Spatial reception parameters.

[0020] The information about a QCL such as those shown in the above QCL types A to D may be called a QCL property.

[0021] The assumption by a UE that a Control Resource Set (CORESET), channel, or reference signal has a specific QCL (e.g., QCL type D) relationship with another CORESET, channel, or reference signal may be referred to as a QCL assumption.

[0022] The UE may determine at least one of a transmit beam (Tx beam) and a receive beam (Rx beam) for a signal / channel based on the TCI condition or QCL assumption of the signal / channel.

[0023] The TCI state may be, for example, information about the QCL between the target channel (in other words, the Reference Signal (RS) for the channel) and another signal (e.g., another RS). The TCI state may be set (indicated) by higher layer signaling, physical layer signaling, or a combination thereof.

[0024] The physical layer signaling may be, for example, Downlink Control Information (DCI).

[0025] The channel for which the TCI state or spatial relationship is set (specified) may be, for example, at least one of a downlink shared channel (Physical Downlink Shared Channel (PDSCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), an uplink shared channel (Physical Uplink Shared Channel (PUSCH)), and an uplink control channel (Physical Uplink Control Channel (PUCCH)).

[0026] Furthermore, the RS that has a QCL relationship with the channel may be, for example, at least one of a Synchronization Signal Block (SSB), a Channel State Information Reference Signal (CSI-RS), a Sounding Reference Signal (SRS), a CSI-RS for tracking (also called a Tracking Reference Signal (TRS)), and a QCL detection reference signal (also called a QRS).

[0027] An SSB is a signal block that includes at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). An SSB may also be referred to as an SS / PBCH block.

[0028] An RS of QCL type X in a TCI state may refer to an RS that has a relationship of QCL type X with (the DMRS of) a certain channel / signal, and this RS may be called a QCL source of QCL type X in the TCI state.

[0029] (L1 / L2 inter-cell mobility) The UE may perform UL transmission to one or more cells / TRPs. The following scenario 1 or scenario 2 may be considered as a procedure in this case. In the present disclosure, the serving cell may be replaced with the TRP in the serving cell. Layer 1 / layer 2 (L1 / L2) and DCI / Medium Access Control Control Element (MAC CE) may be replaced with each other. In the present disclosure, a physical cell identity (PCI) different from the physical cell identity (PCI) of the current serving cell may be simply referred to as a "different PCI." A non-serving cell, a cell having a different PCI, and an additional cell may be replaced with each other.

[0030] <Scenario 1> Scenario 1 corresponds to, for example, multi-TRP inter-cell mobility, but may also be a scenario that does not correspond to multi-TRP inter-cell mobility.

[0031] (1) The UE receives from the serving cell the configuration necessary to use radio resources for data transmission and reception, including SSB configuration for beam measurement of a TRP corresponding to a PCI different from that of the serving cell, and resources of the different PCI. (2) The UE performs beam measurement of the TRPs corresponding to different PCIs and reports the beam measurement results to the serving cell. (3) Based on the above report, the Transmission Configuration Indication (TCI) states associated with the TRPs corresponding to different PCIs are activated by L1 / L2 signaling from the serving cell. (4) The UE transmits and receives using UE-dedicated channels on TRPs corresponding to different PCIs. (5) The UE must always cover the serving cell, including in the case of multiple TRPs. As in conventional systems, the UE must use common channels from the serving cell, such as the Broadcast Control Channel (BCCH) and the Paging Channel (PCH).

[0032] In Scenario 1, when the UE transmits and receives signals to and from an additional cell / TRP (a TRP corresponding to the PCI of the additional cell), the serving cell (the serving cell assumed by the UE) is not changed. The UE is configured with higher layer parameters related to the PCI of non-serving cells from the serving cell. Scenario 1 may be applied, for example, in Rel. 17.

[0033] Figure 1A shows an example of UE movement in Rel. 17. Assume that the UE moves from a cell (serving cell) with PCI #1 to a cell (additional cell) with PCI #3 (which overlaps with the serving cell). In this case, Rel. 17 does not support switching of the serving cell via L1 / L2.

[0034] An additional cell is a cell with an additional PCI that is different from the PCI of the serving cell. The UE can receive / transmit UE-dedicated channels from the additional cell. The UE needs to be within the coverage of the serving cell to receive UE common channels (e.g., system information / paging / short messages). When the UE moves out of the coverage of the serving cell, a cell change is required, for example, by handover (also known as L3 mobility).

[0035] <Scenario 2> In scenario 2, L1 / L2 inter-cell mobility is applied. With L1 / L2 inter-cell mobility, the serving cell can be changed using functions such as beam control without RRC reconfiguration. In other words, transmission and reception with an additional cell is possible without handover. Since handover requires RRC reconnection and creates a period when data communication is unavailable, by applying L1 / L2 inter-cell mobility that does not require handover, data communication can be continued even when the serving cell is changed. Scenario 2 may be applied in Rel. 18, for example. In scenario 2, for example, the following procedure is performed.

[0036] (1) The UE receives from the serving cell the SSB configuration of a cell (additional cell) with a different PCI for beam measurement / serving cell change. (2) The UE performs beam measurements of cells using different PCIs and reports the measurement results to the serving cell. (3) The UE may receive a configuration of a cell with a different PCI (serving cell configuration) through higher layer signaling (e.g., RRC). That is, a pre-configuration regarding a serving cell change may be performed. This configuration may be performed together with the configuration in (1) or separately. (4) Based on the above report, the TCI states of cells with different PCIs may be activated by L1 / L2 signaling according to the change of serving cell. The activation of the TCI states and the change of serving cell may be performed separately. (5) The UE changes the serving cell (assumed serving cell) and starts receiving / transmitting using the pre-configured UE-specific channel and TCI state.

[0037] That is, in Scenario 2, the serving cell (the assumed serving cell in the UE) is updated by L1 / L2 signaling. Scenario 2 may be applied in Rel. 18.

[0038] Figure 1B shows an example of UE mobility in Rel. 18. In Rel. 18, the serving cell is switched by L1 / L2 (e.g., DCI / MAC CE). The UE can receive / transmit UE-dedicated channels / common channels to / from the new serving cell (or target serving cell). The UE may move out of the coverage of the current serving cell (e.g., current serving cell).

[0039] (UE-initiated Beam Report (UEIBR)) It is being considered that future wireless communication systems (e.g., Rel. 19 and later) will support event-based beam reporting, which may also be called event-triggered beam reporting or UE-initiated beam reporting (UEIBR).

[0040] UEIBR / UE initiated beam management (UEIBM) can be used for measurement reporting / beam switching / cell switching etc.

[0041] The UEIBR considers that the report content will include at least one of the following information in the beam report: Beam / reference signal index (e.g., CSI-RS / SSB resource index / indicator). Measurement results (e.g., L1-RSRP / SINR (absolute value / relative value)). · Number of beams / RS reported. · Whether the serving beam is included in the beam reporting.

[0042] Regarding the information regarding the number of beams / RSs to be reported, since the base station / network and the UE need to have a common understanding of the size of the beam report (e.g., UCI), it is preferable that this information be included in the beam report reported from the UE.

[0043] In this case, the UCI may be reported in two parts. For example, the UCI (which may have a fixed size) transmitted in the first part (step) may indicate the size (e.g., the number of beams) of the UCI transmitted in the second part (step).

[0044] In this case, the UCI may be coded in two parts. For example, the size of the second part of the UCI may be indicated by the first part of the UCI (which may have a fixed size).

[0045] Events related to UEIBR (as mentioned above) may be broadly categorized into the following event types: Event 1: The quality of the current beam becomes worse than a certain threshold. Event 2: The quality of at least one new beam (e.g., L1-RSRP) becomes better than a certain threshold compared to the quality of the current beam. Event 3: The quality of the new beam is better than a certain threshold. Event 4: The quality of the current beam becomes worse than a first threshold and the quality of at least one new beam becomes better than a second threshold. Event 5: The absolute value of the difference between the quality of the current beam and the quality of at least one new beam falls below a certain threshold. Event 6: The current beam is no longer among the best K (more than 1: K>1) beams (among those configured for measurement / reporting). Event 7: The quality of at least one new beam (e.g., L1-RSRP) becomes better than the RS derived from the best quality activated (active) TCI state up to Mth (M >= 1, M may be configured by RRC) by more than a threshold. Event 8: The quality (e.g., L1-RSRP) of M (more than 1: M>1) new beams becomes better than the current beam by more than a threshold. Event 9: The quality of at least one new beam (e.g. L1-RSRP) becomes better than the configured reference RS (which may be SSB / CSI-RS) by more than a threshold.

[0046] It should be noted that such event types do not exclude the events described above. For example, such event types may be appropriately interpreted as the events described above.

[0047] Furthermore, at least two of the above events may be defined in combination.

[0048] (Event-triggered beam reporting for mobility) The above-mentioned UEIBR (Event Triggered Beam Report) can also be extended for mobility.

[0049] For example, the following LTM events based on the beam quality of the serving cell and candidate cell are supported as L1 LTM measurement events. Event LTM2: The beam quality of the serving cell becomes worse than the absolute threshold. · Event LTM3: The beam of the candidate cell is better than the beam of the serving cell by an offset. · Event LTM4: The beam of the candidate cell becomes better than the absolute threshold. · Event LTM5: The beam of the serving cell deteriorates below an absolute threshold 1 (the first absolute threshold), and the beam of the candidate cell improves beyond another absolute threshold 2 (the second absolute threshold).

[0050] In addition to the events described above, consideration is being given to which beam of the serving cell and adjacent cells is used for event evaluation, or to the necessity of Event LTM1.

[0051] (L1L2-triggered mobility (LTM) in Rel.18) Figure 2 is a diagram showing an example of LTM being considered in Rel.18. Here, as the operations of LTM, steps of LTM preparation (e.g., LTM preparation), early sync (e.g., Early sync), LTM execution (e.g., LTM execution), and LTM completion (e.g., LTM completion) are shown, but the steps of LTM are not limited to this. Some steps (or operations included in the steps) may be omitted, the order of operations included in some steps and other operations included in other steps may be swapped, or other steps (or other operations) may be added. Note that in the present disclosure, early sync may be read as sync.

[0052] <LTM preparation> 1: The UE transmits a measurement report message to the gNB. The gNB determines the LTM settings and starts preparing one or more candidate cells.

[0053] 2: The gNB transmits an RRC reconfiguration message including the LTM candidate cell settings of one or more candidate cells to the UE.

[0054] 3: The UE saves its LTM candidate cell settings and transmits an RRC reconfiguration complete message to the gNB.

[0055] <Early sync> 4a: Before receiving the cell switch command, the UE performs DL synchronization with one or more candidate cells. DL synchronization for candidate cells before the cell switch command may be supported with at least SSB-based implementation.

[0056] 4b: When requested by the network, the UE performs early TA acquisition with one or more candidate cells before receiving the cell switch command. This is triggered via CFRA by the PDCCH order from the source cell. Next, the UE transmits a preamble to the indicated candidate cell. To minimize data interruption of the source cell by Contention Free Random Access (CFRA) to the candidate cell, the UE does not receive a RAR for the purpose of TA value acquisition. The TA value of the candidate cell is indicated in the cell switch command. The UE does not maintain a TA timer for the candidate cell and guarantees the validity of TA based on the network implementation.

[0057] <LTM execution> 5: The UE performs L1 measurements set for the candidate cell and transmits an L1 measurement report to the gNB. The L1 measurements are performed as long as the RRC reconfiguration in step 2 is applied.

[0058] 6: The gNB decides to execute a cell switch to the target cell and transmits a MAC CE (cell switch command) to trigger the cell switch. The MAC CE includes a candidate setting of the index of the target cell. The UE switches to the target cell and applies the setting indicated by the candidate setting index.

[0059] 7: If the UE does not have a valid TA for the target cell, it performs a random access procedure on the target cell.

[0060] <LTM completion> 8: The UE completes the LTM cell switch procedure by sending an RRC reconfiguration complete message. The UE performs the RA procedure in step 7, and considers the LTM execution to be completed successfully if the random access procedure is successfully completed. In RACH-less LTM, the UE considers the LTM execution to be completed successfully if the network determines that the first UL data has been successfully received. The UE determines the successful reception of the first UL data by receiving a PDCCH specifying the UE's C-RNTI in the target cell that schedules the next new transmission of the first UL data.

[0061] (Conditional Handover (CHO)) This section explains Conditional Handover (CHO) in Rel. 16 and later. CHO is applied to, for example, Non-Terrestrial Networks (NTN). NTN supports the following additional trigger conditions for a UE to perform CHO to a candidate cell: Radio Resource Management (RRM) measurement-based event A4. Time-based trigger conditions. Location-based trigger conditions.

[0062] A time-based or location-based trigger condition is always configured together with one of the measurement-based trigger conditions (CHO events A3 / A4 / A5 described below). How the UE evaluates the time-based or location-based trigger conditions together with the RRM measurement-based events is up to the UE implementation.

[0063] (Rel.18 LTM and Rel.16 CHO) While the above-mentioned LTM (e.g., Rel. 18 LTM) supports early sync / early L1 measurement report, CHO (e.g., Rel. 16 CHO) does not support early sync / early measurement report. In LTM, mobility decisions are made by the network (based on L1 beam reports), while in CHO, they are made by the UE (based on L3 measurement results and CHO conditions).

[0064] In LTM, a MAC CE for cell switch command is transmitted from the base station to the UE. In CHO, the UE starts evaluating the conditions for performing CHO for candidate cells after receiving the CHO configuration through RRC signaling. After deciding on mobility (or cell switch), CHO requires a RACH, but LTM may not require a RACH.

[0065] (conditional LTM) In the case where conditional LTM (eg, conditional LTM (CLTM)) is supported, an example of providing / signaling / evaluating execution conditions (eg, execution conditions) for candidate cells will be described.

[0066] Execution conditions may be set for each candidate cell by RRC signaling / MAC CE. The execution conditions (or may simply be called "conditions") may include at least one of an event, a reference signal type (RS type), a reference signal configuration (RS configuration), and a measurement quantity. The reference signal type (RS type) may indicate SSB / CSI-RS. The measurement quantity may indicate L1-RSRP / L3-RSRP / SINR / RSRQ.

[0067] The implementation conditions may be set separately for each candidate cell (e.g., the setting of different conditions may be supported). Alternatively, the implementation conditions may be set commonly for multiple candidate cells (e.g., a candidate cell group) or for all candidate cells. Alternatively, some of the implementation conditions may be set commonly for each candidate cell, and the remaining implementation conditions may be set separately. Some of the implementation conditions may be events, and the remaining implementation conditions may be condition values, etc. Of course, this is not limited to this.

[0068] The number of candidate cells for which the enabling condition is provided may be predefined in a specification, may be configured in the UE by a network (e.g., a base station), or may be determined based on UE capabilities. For example, the number of cells for which the enabling condition is provided may be the same as the configured candidate cells, or may be less than all the configured candidate cells.

[0069] The settings for the implementation conditions (e.g., detailed settings) may be the same as the condition settings of the existing system. The condition settings of the existing system may be, for example, the condition settings supported by CHO supported in Rel. 16 (e.g., condition settings based on L3 measurement).

[0070] Alternatively, a new condition setting similar to that for an event-triggered L1 report may be applied to the setting of the execution condition. An example of the condition (or event) is shown below. Event A2: The serving cell measurement is worse than the threshold. Event A3: The measurement result of the neighboring cell (the measurement result plus an offset) is better than the measurement result of the SpCell (the measurement result plus an offset). Event A4: The measurement result of the neighboring cell (the measurement result plus an offset) is better than the threshold. Event A5: The measurement result of SpCell is worse than the first threshold, and the measurement result of the neighboring cell (a value obtained by adding an offset to the measurement result) is better than the second threshold. Event A6: The measurement result of the neighboring cell (a value obtained by adding an offset to the measurement result) is better than the measurement result of the serving cell (Secondary Cell (SCell)) (a value obtained by adding an offset to the measurement result). Event I1: The interference measurement is higher than the threshold. Event A4': The measurement result of one beam from the neighboring cell is better than the threshold. Event A4: The statistical value (e.g., average, sum, etc.) of the measurement results of multiple beams (e.g., the best X beams) is better than a threshold. X may be fixed or configurable by higher layer signaling, etc. Event A4': The L1-RSRP measurement result of one beam from a neighboring cell is better than the threshold. Event A4''): The L1-RSRP of each of the X beams from the neighboring cells is better than the threshold.

[0071] It should be noted that the applicable conditions / events are not limited to these, and a combination of the above events may be applied, or other events may be applied.

[0072] For the condition for each candidate cell (or for multiple / all candidate cells), the condition (or event) to be set may be determined based on at least one of options 1 and 2 below.

[0073] [Option 1] One condition may be set for each candidate cell (or for multiple / all candidate cells), and the condition may correspond to only one event, i.e., one condition having only one event may be set for each candidate cell (or for multiple / all candidate cells).

[0074] When a condition corresponding to each candidate cell (or an event corresponding to the condition) is satisfied, the UE / base station may control to perform an LTM procedure / action for the candidate cell.

[0075] [Option 2] Multiple conditions (e.g., up to X conditions) may be set for each candidate cell (or for multiple / all candidate cells). X may be, for example, 2 or 3, or may be 4 or more. X may be defined in a specification, may be set to the UE by the base station, or may be determined based on the UE capabilities.

[0076] When at least one of a plurality of conditions (or events corresponding to each condition) corresponding to each candidate cell is satisfied, the UE / base station may be controlled to perform an LTM procedure / action for the candidate cell.

[0077] When multiple (e.g., X) conditions are supported for each candidate cell, restrictions may be placed between the multiple conditions. The restrictions between the conditions may be, for example, RS configuration / RS type / event / measurement quantity. For example, the same RS configuration / RS type may be set between the multiple conditions, and different event / measurement quantities may be set between the multiple conditions.

[0078] When different conditions correspond to different candidate cells, restrictions may be imposed between the conditions, or restrictions may not be imposed between the conditions.

[0079] The supported conditions (eg, RS configuration / RS type / event / measurement quantity), the number of conditions to be set may be according to the UE capability.

[0080] Below, an example of the operation of the conditional LTM will be explained, but parts that are not particularly explained may be the same as the procedure of the Rel. 18 LTM (R18 LTM) shown in FIG.

[0081] [Conditional LTM operation example 1] Figure 3 is a diagram showing a first example of conditional LTM operation. In Figure 3, the conditional LTM operation includes steps of LTM preparation (e.g., CLTM preparation), early synchronization (e.g., early sync), LTM execution (e.g., CLTM execution), and LTM completion (e.g., CLTM completion), but the LTM steps are not limited to these. Some steps (or actions included in steps) may be omitted, the order of actions included in some steps may be reversed with other actions included in other steps, or other steps (or other actions) may be added.

[0082] 《LTM preparation》 In the LTM preparation, a UE connected to a serving cell via RRC (e.g., a UE in RRC_CONNECTED) transmits a measurement report. The measurement report may be an L3 measurement report. The base station (or source base station / serving cell) performs LTM candidate preparation (e.g., LTM candidate preparation) based on the measurement report transmitted from the UE.

[0083] The base station performs LTM candidate configuration (e.g., LTM candidate configuration) and execution conditions (e.g., execution conditions) for candidate cells through RRC (e.g., RRC reconfiguration). Information about candidate cells may be configured in the UE through the LTM candidate configuration. Execution conditions may be configured in the UE for each candidate cell (or for multiple / all candidate cells) through the configuration of execution conditions for candidate cells.

[0084] Option 1 / Option 2 may be applied to the setting of implementation conditions for candidate cells.

[0085] 《Early sync》 The UE performs early synchronization (e.g., early sync) with the candidate cell. DL / UL early synchronization with the candidate cell may be performed by the UE after RRC configuration (e.g., RRC reconfiguration) of the LTM candidate cell.

[0086] LTM execution The UE performs measurements (e.g., L1 measurements) on the configured candidate cells and transmits a measurement report, which may be an L1 measurement report.

[0087] The base station (or source base station / serving cell) makes a conditional LTM (CLTM) decision based on the measurement report sent from the UE. For example, the base station determines the conditional LTM for one or more candidate target cells for which the enabling condition can be evaluated (or for which the UE needs to evaluate the enabling condition). The one or more candidate target cells for which the enabling condition can be evaluated may be determined based on the measurement report sent from the UE.

[0088] The base station may transmit a predetermined MAC CE to the UE. The base station may use the predetermined MAC CE to indicate to the UE information regarding one or more candidate target cells for conditional LTM (or for which an implementation condition is to be evaluated). The predetermined MAC CE may trigger the UE to evaluate the implementation condition.

[0089] The UE may initiate an implementation evaluation for candidate target cells indicated by a predetermined MAC CE. If a target cell satisfies the implementation condition, the UE may implement LTM (or mobility) for the target cell. For example, if a candidate cell satisfies the implementation condition, the UE may detach (e.g., detach) from a source (e.g., source cell) and apply the configurations (e.g., target configurations) of the target cell to which the handover is to be performed.

[0090] For example, if a given MAC CE indicates multiple candidate cells (or candidate target cells), the UE may determine a specific target cell to be targeted for mobility / cell switch by considering the implementation conditions corresponding to each candidate cell (or the implementation conditions common to the multiple candidate cells).The given MAC CE may indicate the implementation conditions / events corresponding to each candidate cell (or the implementation conditions common to the multiple candidate cells).

[0091] The UE may perform a random access procedure (RACH-based CLTM) to the selected (eg, switched to) target cell.

[0092] For example, if the UE does not have a valid Timing Advance (TA) for the target cell / candidate cell (or a destination cell), it may perform a random access procedure to obtain a TA value for the target cell. On the other hand, if the UE has a valid Timing Advance for the target cell / candidate cell (or a destination cell), it may not perform the random access procedure (or may omit / skip the random access procedure). Note that the random access procedure may be performed if the UE has a valid TA for the target cell.

[0093] After receiving a predetermined MAC CE, the UE may determine whether to apply a random access procedure based on at least one of the predetermined MAC CE and an RRC parameter (e.g., an RRC parameter related to the setting of a TA acquisition method). For example, the UE may determine whether to apply a random access procedure based on a value of a predetermined field (e.g., a timing advance command field) included in the predetermined MAC CE. The UE may also determine whether to apply a random access procedure based on a TA acquisition method set by an RRC parameter (or the TA acquisition method and the value of a predetermined field of the predetermined MAC CE).

[0094] Note that, in FIG. 3, a case where a candidate target cell for conditional LTM (or a candidate target cell for evaluating implementation conditions) is indicated by MAC CE is shown, but this is not limited to this. For example, information on a candidate target cell for conditional LTM may be indicated to a UE by DCI. Alternatively, MAC CE may indicate a correspondence (or mapping) between information on candidate target cells for multiple conditional LTMs (or candidate target cells and implementation conditions for multiple conditional LTMs) and a code point in a predetermined field of DCI, and a candidate target cell for a specific conditional LTM may be indicated by DCI.

[0095] 《LTM completion》 The LTM cell switch procedure may be completed by the UE sending a predetermined message to the target cell / candidate cell.

[0096] For RACH-based LTM, the UE may determine that the LTM implementation is completed successfully if the random access procedure is completed successfully.

[0097] For RACH-less (e.g., RACH-less) LTM, the UE may determine that the LTM has been successfully performed if the UE determines that the network has successfully received the first UL data. For example, for RACH-less LTM, the UE may transmit the first data to the target cell along with sending an RRC reconfiguration complete message. The UE may determine that the first UL data has been successfully received by receiving a PDCCH in the target cell that addresses the UE's C-RNTI. This PDCCH corresponds to the PDCCH that schedules a new transmission following the first UL data.

[0098] [Conditional LTM operation example 2] Figure 4 is a diagram showing a second example of conditional LTM operation. Figure 4 shows the steps of LTM preparation (e.g., CLTM preparation), early sync and LTM execution (e.g., early sync and CLTM execution), and LTM completion (e.g., CLTM completion) as the conditional LTM operation, but the LTM steps are not limited to these. Some steps (or actions included in steps) may be omitted, the order of actions included in some steps may be reversed with other actions included in other steps, or other steps (or other actions) may be added.

[0099] 《LTM preparation》 This can be done similarly to the LTM preparation in Figure 3.

[0100] Early sync and LTM execution The UE performs early synchronization (eg, early sync) with the candidate cell and performs LTM.

[0101] The UE may perform DL early synchronization with the LTM candidate cell after RRC configuration (e.g., RRC reconfiguration) of the candidate cell. For example, the UE may perform DL synchronization with the configured candidate cell.

[0102] The UE performs measurements (e.g., L1 measurements) on the configured candidate cells and transmits a measurement report, which may be an L1 measurement report.

[0103] The base station (or source base station / serving cell) makes a conditional LTM (CLTM) decision based on the measurement report sent from the UE. For example, the base station determines the conditional LTM for one or more candidate target cells for which the enabling condition can be evaluated (or for which the UE needs to evaluate the enabling condition). The one or more candidate target cells for which the enabling condition can be evaluated may be determined based on the measurement report sent from the UE.

[0104] The base station may transmit a predetermined MAC CE to the UE. The base station may use the predetermined MAC CE to indicate to the UE information regarding one or more candidate target cells for conditional LTM (or for which an implementation condition is to be evaluated). The predetermined MAC CE may trigger the UE to evaluate the implementation condition.

[0105] The UE may perform DL synchronization with the LTM candidate cell after RRC configuration (e.g., RRC reconfiguration) of the candidate cell. In this case, the UE may perform UL synchronization with the candidate target cell for conditional LTM indicated by a predetermined MAC CE. In this way, by performing UL synchronization after receiving a predetermined MAC CE, it is possible to reduce the number of cells for which UL synchronization is performed.

[0106] The UE may also start implementation evaluation for candidate target cells indicated by a predetermined MAC CE. If there is a target cell that satisfies an implementation condition, the UE may perform LTM (or mobility) for the target cell. For example, if the implementation condition is satisfied, the UE may detach (e.g., detach) from a source (e.g., source cell) and apply the configuration (e.g., target configurations) of the target cell to which the handover is to be performed. Note that the UE may perform UL synchronization after the implementation evaluation.

[0107] For example, if a given MAC CE indicates multiple candidate cells (or candidate target cells), the UE may determine a specific target cell to be targeted for mobility / cell switch by considering the implementation conditions corresponding to each candidate cell (or the implementation conditions common to the multiple candidate cells).The given MAC CE may indicate the implementation conditions / events corresponding to each candidate cell (or the implementation conditions common to the multiple candidate cells).

[0108] The UE may perform a random access procedure (RACH-based CLTM) to the selected (eg, switched to) target cell.

[0109] For example, if the UE does not have a valid Timing Advance (TA) for the target cell / candidate cell (or a destination cell), it may perform a random access procedure to obtain a TA value for the target cell. On the other hand, if the UE has a valid Timing Advance for the target cell / candidate cell (or a destination cell), it may not perform the random access procedure (or may omit / skip the random access procedure). Note that the random access procedure may be performed if the UE has a valid TA for the target cell.

[0110] After receiving a predetermined MAC CE, the UE may determine whether to apply a random access procedure based on at least one of the predetermined MAC CE and an RRC parameter (e.g., an RRC parameter related to the setting of a TA acquisition method). For example, the UE may determine whether to apply a random access procedure based on a value of a predetermined field (e.g., a timing advance command field) included in the predetermined MAC CE. The UE may also determine whether to apply a random access procedure based on a TA acquisition method set by an RRC parameter (or the TA acquisition method and the value of a predetermined field of the predetermined MAC CE).

[0111] Note that, in FIG. 4, a case where a candidate target cell for conditional LTM (or a candidate target cell for evaluating implementation conditions) is indicated by MAC CE is shown, but this is not limited to this. For example, information on a candidate target cell for conditional LTM may be indicated to a UE by DCI. Alternatively, MAC CE may indicate a correspondence (or mapping) between information on a candidate target cell for multiple conditional LTMs (or a candidate target cell and implementation conditions for multiple conditional LTMs) and a code point in a predetermined field of DCI, and a candidate target cell for a specific conditional LTM may be indicated by DCI.

[0112] 《LTM completion》 This can be done in the same way as the LTM completion in Figure 3.

[0113] [Example of target cell behavior in conditional LTM] Figure 5 is a diagram showing an example of the operation of a target cell in conditional LTM. Figure 5 shows the steps of LTM preparation (e.g., CLTM preparation), early synchronization (e.g., early synchronization), LTM execution (e.g., CLTM execution), and LTM completion (e.g., CLTM completion) (the example of Figure 3) as the operation of conditional LTM, but the steps of LTM are not limited to these. Some steps (or operations included in steps) may be omitted, the order of operations included in some steps may be reversed with other operations included in other steps (e.g., the example of Figure 4), or other steps (or other operations) may be added.

[0114] 《LTM preparation》 In the LTM preparation, a UE that is RRC connected to a serving cell (e.g., a UE in RRC_CONNECTED) sends a measurement report, which may be an L3 measurement report.

[0115] The base station (or source base station / serving cell) prepares an LTM candidate (e.g., LTM candidate preparation) based on the measurement report transmitted from the UE. In this case, information may be exchanged / shared among multiple candidate cells (which may include the serving cell). The information exchanged / shared among multiple candidate cells may be at least one of information about the measurement report reported from the UE, information about the configuration of the candidate cell to be configured, and information about the implementation conditions for each candidate cell.

[0116] The base station performs LTM candidate configuration (e.g., LTM candidate configuration) and execution conditions (e.g., execution conditions) for candidate cells through RRC (e.g., RRC reconfiguration). Information about candidate cells may be configured in the UE through the LTM candidate configuration. Execution conditions may be configured in the UE for each candidate cell (or for multiple / all candidate cells) through the configuration of execution conditions for candidate cells.

[0117] Option 2-1 / Option 2-2 may be applied to the setting of implementation conditions for candidate cells.

[0118] 《Early sync》 The UE performs early synchronization (e.g., early sync) with the candidate cell. DL / UL early synchronization with the candidate cell may be performed by the UE after RRC configuration (e.g., RRC reconfiguration) of the LTM candidate cell. UL early synchronization may be performed after sending a measurement report (e.g., L1 measurement report) in the LTM implementation step or after receiving a predetermined MAC CE.

[0119] LTM execution The UE performs measurements (e.g., L1 measurements) on the configured candidate cells and transmits a measurement report, which may be an L1 measurement report.

[0120] The base station (or source base station / serving cell) makes a conditional LTM (CLTM) decision based on the measurement report sent from the UE. For example, the base station determines the conditional LTM for one or more candidate target cells for which the enabling condition can be evaluated (or for which the UE needs to evaluate the enabling condition). The one or more candidate target cells for which the enabling condition can be evaluated may be determined based on the measurement report sent from the UE.

[0121] The base station may transmit a predetermined MAC CE to the UE. The base station may use the predetermined MAC CE to indicate to the UE information regarding one or more candidate target cells for conditional LTM (or for which an implementation condition is to be evaluated). The predetermined MAC CE may trigger the UE to evaluate the implementation condition.

[0122] The base station may also notify the candidate cell of information related to the conditional LTM (CLTM) decision. For example, the base station may notify the candidate cell of information related to one or more candidate target cells for the conditional LTM (or for which the implementation conditions are evaluated). The candidate cells to which the information is notified may be limited to candidate cells selected as candidate cells for the conditional LTM (CLTM), or may not be limited to such candidate cells (for example, the information may also be notified to candidate cells that are not selected as candidate cells for the conditional LTM (CLTM)).

[0123] The UE may initiate an implementation evaluation for candidate target cells indicated by a predetermined MAC CE. If a target cell satisfies an implementation condition, the UE may implement LTM (or mobility) for the target cell. For example, if the implementation condition is met, the UE may detach (e.g., detach) from a source (e.g., source cell) and apply the configurations (e.g., target configurations) of the target cell to which the handover is to be performed.

[0124] The UE may perform a random access procedure to the selected (e.g., target) target cell. For example, if the UE does not have a valid timing advance for the target / candidate cell (or a destination cell), the UE may perform the random access procedure to obtain a TA value for the target cell. On the other hand, if the UE has a valid timing advance (TA) for the target / candidate cell (or a destination cell), the UE may not perform the random access procedure (or may omit / skip the random access procedure).

[0125] After receiving a predetermined MAC CE, the UE may determine whether to apply a random access procedure based on at least one of the predetermined MAC CE and an RRC parameter (e.g., an RRC parameter related to the setting of a TA acquisition method). For example, the UE may determine whether to apply a random access procedure based on a value of a predetermined field (e.g., a timing advance command field) included in the predetermined MAC CE. The UE may also determine whether to apply a random access procedure based on a TA acquisition method set by an RRC parameter (or the TA acquisition method and the value of a predetermined field of the predetermined MAC CE).

[0126] Note that, here, the case where a candidate target cell for conditional LTM (or a candidate target cell for evaluating implementation conditions) is indicated by MAC CE has been shown, but this is not limiting. For example, information on a candidate target cell for conditional LTM may be indicated to a UE by DCI. Alternatively, the MAC CE may indicate a correspondence (or mapping) between information on a candidate target cell for multiple conditional LTMs (or a candidate target cell and implementation conditions for multiple conditional LTMs) and a code point in a predetermined field of DCI, and a candidate target cell for a specific conditional LTM may be indicated by DCI.

[0127] 《LTM completion》 The LTM cell switch procedure may be completed by the UE sending a predetermined message to the selected (e.g., switched to) target cell / candidate cell.

[0128] For RACH-based LTM, the UE may determine that the LTM implementation is completed successfully if the random access procedure is completed successfully.

[0129] [Conditional LTM operation example 3] FIG. 6 is a diagram showing a third example of conditional LTM operation. In FIG. 6, the conditional LTM operation includes steps of LTM preparation (e.g., CLTM preparation), early synchronization (e.g., early sync), LTM execution (e.g., CLTM execution), and LTM completion (e.g., CLTM completion), but the LTM steps are not limited to these. Some steps (or operations included in steps) may be omitted, the order of operations included in some steps and other operations included in other steps may be reversed, or other steps (or other operations) may be added. Also, FIG. 6 may be suitably applied to RACH-less CLTM.

[0130] 《LTM preparation》 In the LTM preparation, a UE connected to a serving cell via RRC (e.g., a UE in RRC_CONNECTED) transmits a measurement report. The measurement report may be an L3 measurement report. The base station (or source base station / serving cell) performs LTM candidate preparation (e.g., LTM candidate preparation) based on the measurement report transmitted from the UE.

[0131] The base station performs LTM candidate configuration (e.g., LTM candidate configuration) and execution conditions (e.g., execution conditions) for candidate cells through RRC (e.g., RRC reconfiguration). Information about candidate cells may be configured in the UE through the LTM candidate configuration. Execution conditions may be configured in the UE for each candidate cell (or for multiple / all candidate cells) through the configuration of execution conditions for candidate cells.

[0132] Option 1 / Option 2 may be applied to the setting of implementation conditions for candidate cells.

[0133] 《Early sync》 The UE performs early synchronization (e.g., early sync) with the candidate cell. DL / UL early synchronization with the candidate cell may be performed by the UE after RRC configuration (e.g., RRC reconfiguration) of the LTM candidate cell. UL early synchronization may be performed after sending a measurement report (e.g., L1 measurement report) in the LTM implementation step or after receiving a predetermined MAC CE.

[0134] LTM execution The UE performs measurements (e.g., L1 measurements) on the configured candidate cells and transmits a measurement report, which may be an L1 measurement report.

[0135] The base station (or source base station / serving cell) makes a conditional LTM (CLTM) decision based on the measurement report sent from the UE. For example, the base station determines the conditional LTM for one or more candidate target cells for which the enabling condition can be evaluated (or for which the UE needs to evaluate the enabling condition). The one or more candidate target cells for which the enabling condition can be evaluated may be determined based on the measurement report sent from the UE.

[0136] The base station may transmit a predetermined MAC CE to the UE. The base station may use the predetermined MAC CE to indicate to the UE information regarding one or more candidate target cells for conditional LTM (or for which an implementation condition is to be evaluated). The predetermined MAC CE may trigger the UE to evaluate the implementation condition.

[0137] The UE may initiate an implementation evaluation for candidate target cells indicated by a predetermined MAC CE. If a target cell satisfies an implementation condition, the UE may implement LTM (or mobility) for the target cell. For example, if the implementation condition is met, the UE may detach (e.g., detach) from a source (e.g., source cell) and apply the configurations (e.g., target configurations) of the target cell to which the handover is to be performed.

[0138] After the UE determines mobility or cell switch (or selects a new target cell) based on the evaluation of the implementation conditions, the UE may send at least one of a message regarding RRC reconfiguration completion (e.g., RRCReconfigurationComplete) and a MAC CE (e.g., new MAC CE) to the new target cell, which may instruct the new target cell to make a CLTM decision for the UE.

[0139] 《LTM completion》 The LTM cell switch procedure may be completed by the UE sending a predetermined message / MAC CE to the target cell / candidate cell.

[0140] In the case of RACH-less (e.g., RACH-less) LTM, the UE may determine that the LTM has been successfully performed if the UE determines that the network has successfully received the first UL data. For example, in the case of RACH-less LTM, the UE may transmit the first data to the target cell along with an RRC reconfiguration complete message / MAC CE. The UE may determine that the first UL data has been successfully received by receiving a PDCCH in the target cell that addresses the UE's C-RNTI. This PDCCH corresponds to the PDCCH that schedules a new transmission following the first UL data.

[0141] [Conditional LTM operation example 4] FIG. 7 is a diagram showing a fourth example of conditional LTM operation. In FIG. 7, the conditional LTM operation includes steps of LTM preparation (e.g., CLTM preparation), early synchronization (e.g., early sync), LTM execution (e.g., CLTM execution), and LTM completion (e.g., CLTM completion), but the LTM steps are not limited to these. Some steps (or operations included in steps) may be omitted, the order of operations included in some steps and other operations included in other steps may be reversed, or other steps (or other operations) may be added. Also, FIG. 7 may be suitably applied to RACH-less CLTM.

[0142] 《LTM preparation》 This can be done similarly to the LTM preparation in Figure 6.

[0143] 《Early sync》 This can be done in the same way as the early synchronization in FIG.

[0144] LTM execution The UE performs measurements (e.g., L1 measurements) on the configured candidate cells and transmits a measurement report, which may be an L1 measurement report.

[0145] The base station (or source base station / serving cell) makes a conditional LTM (CLTM) decision based on the measurement report sent from the UE. For example, the base station determines the conditional LTM for one or more candidate target cells for which the enabling condition can be evaluated (or for which the UE needs to evaluate the enabling condition). The one or more candidate target cells for which the enabling condition can be evaluated may be determined based on the measurement report sent from the UE.

[0146] The base station may transmit a predetermined MAC CE to the UE. The base station may use the predetermined MAC CE to indicate to the UE information regarding one or more candidate target cells for conditional LTM (or for which an implementation condition is to be evaluated). The predetermined MAC CE may trigger the UE to evaluate the implementation condition.

[0147] The UE may initiate an implementation evaluation for candidate target cells indicated by a predetermined MAC CE. If a target cell satisfies an implementation condition, the UE may implement LTM (or mobility) for the target cell. For example, if the implementation condition is met, the UE may detach (e.g., detach) from a source (e.g., source cell) and apply the configurations (e.g., target configurations) of the target cell to which the handover is to be performed.

[0148] After the UE makes a mobility or cell switch decision (or selects a new target cell) based on the evaluation of the implementation conditions, the UE may transmit a predetermined MAC CE to the current serving cell (e.g., the serving cell before the cell switch). The MAC CE may indicate the UE's CLTM decision to the current serving cell. The predetermined MAC CE may include at least one of information about the selected target cell and information about the latest L1 beam measurement, event-triggered L1 beam measurement, or L1 beam measurement report result.

[0149] After transmitting a predetermined MAC CE to the current serving cell, the UE may start a predetermined timer (or a new timer) and start monitoring the PDCCH transmitted from the reported / instructed new target cell. For example, the UE may start a predetermined timer after transmitting a predetermined MAC CE and perform control so as to monitor the PDCCH until the predetermined timer expires.

[0150] 《LTM completion》 If the UE detects a DCI format (e.g., DCI format 1_0 / 0_0) to which the C-RNTI is applied from the target cell before the predetermined timer expires, the UE may determine that the CLTM is successful (or that the CLTM is completed). Otherwise, the UE may determine that the CLTM is unsuccessful.

[0151] [Conditional LTM operation example 5] FIG. 8 is a diagram showing a fifth example of conditional LTM operation. In FIG. 8, the steps of LTM preparation (e.g., CLTM preparation), early synchronization (e.g., early sync), and LTM execution (e.g., CLTM execution) are shown as CLTM operation, but the LTM steps are not limited to these. Some steps (or operations included in steps) may be omitted, the order of operations included in some steps may be reversed with other operations included in other steps, or other steps (or other operations) may be added. For example, at least some of the processes shown in FIGS. 3 to 7 may be added.

[0152] 《LTM preparation》 In preparing for LTM, a UE connected to a serving cell via RRC (e.g., a UE in RRC_CONNECTED) transmits a measurement report. The measurement report may be an L3 measurement report. The base station (or source base station / serving cell) determines whether to perform LTM based on the measurement report transmitted from the UE.

[0153] The base station (Source gNB) sends an RRC reconfiguration message to the UE containing the LTM candidate cell configuration for one or more candidate cells. The UE saves the LTM candidate cell configuration and sends an RRC reconfiguration complete message to the gNB. The base station (Source gNB) sends signaling containing the LTM candidate cell configuration to the base station (Candidate gNB) of the candidate cell.

[0154] 《Early sync》 The UE performs early synchronization (e.g., early sync) with the candidate cell. DL / UL early synchronization with the candidate cell may be performed by the UE after RRC configuration (e.g., RRC reconfiguration) of the LTM candidate cell.

[0155] LTM execution The UE evaluates whether the event is satisfied, and if so, transmits a second UL signal (e.g., UL cell switch command, event trigger report) to the base station (Source gNB) notifying the possibility of cell switch using the RS / TCI state of the candidate cell. Then, the base station (Source gNB) transmits signaling including the target cell ID and TCI state ID to the base station (Candidate gNB) of the candidate cell.

[0156] Since the UE can transmit an UL signal notifying the possibility of a cell switch before the cell switch decision, there is no need to transmit an UL signal when the LTM cell switch decision is made. In other words, it is possible to avoid the gNB being unable to receive the UL signal when the UE is at the cell edge. The base station (Source gNB) can forward the above signaling including the target cell ID and TCI state ID to the base station (Candidate gNB) (Target gNB) before the cell switch decision is made, so the target gNB can quickly secure resources for the UE. Note that in Rel8 LTM, this signaling is forwarded when the LTM cell switch decision is made.

[0157] The UE evaluates whether a second event is met and, if so, determines to perform an LTM cell switch. The second event may be the same as or different from the first event. For example, the UE may determine to perform an LTM cell switch and perform a cell switch procedure when the event is met for a predetermined time, or when all events are met within a predetermined time.

[0158] The UE applies the target cell configuration, and the UE, the base station (Source gNB), and the base station (Candidate gNB) (Target gNB) perform a cell switch procedure.

[0159] The event for transmitting the first UL signal and the event for transmitting the second UL signal may be the same or different, and the event for transmitting the first UL signal and the condition for performing the cell switch procedure after transmitting the second UL signal may be the same.

[0160] (TA acquisition) It is also possible that the UE performs UL transmission of a candidate cell while taking into account the TA corresponding to the candidate cell. When taking into account the TA of the candidate cell, the UE needs to acquire the TA of the candidate cell (for example, TA acquisition of candidate cells).

[0161] To acquire the TA of a candidate cell, several TA acquisition methods are possible, such as TA acquisition using RACH (e.g., RACH-based solutions) and TA acquisition without using RACH (RACH-less solutions). For TA acquisition using RACH, a method with RAR monitoring and a method without RAR monitoring may be supported. The TA acquisition method may be interpreted as a TA acquisition scheme, a TA acquisition type, or a TA acquisition procedure. In the present disclosure, TA acquisition, TA measurement, TA calculation, TA computation, and TA determination may be interpreted as interchangeable terms.

[0162] For example, the UE may acquire the TA of a candidate cell by transmitting a RACH (e.g., a PDCCH ordered RACH) indicated / triggered by a PDCCH to the candidate cell. Information about the TA of the candidate cell (e.g., a TA value) may be included in a response signal (e.g., an RAR) of the RACH. The RAR may be transmitted from the serving cell or the candidate cell. Alternatively, the TA of the candidate cell may be acquired using a RACH triggered by the UE or a RACH triggered by a higher layer from the network. The PDCCH order may be triggered only by the source cell (or the serving cell).

[0163] Alternatively, the UE may acquire the TA of the candidate cell by transmitting a signal other than the RACH to the candidate cell. Information regarding the TA of the candidate cell (e.g., a TA value) may be instructed to the UE from the base station. As a signal other than the RACH, for example, SRS may be applied (e.g., SRS-based TA measurement).

[0164] Alternatively, the UE may measure / calculate / obtain the TA for the candidate cell based on DL signals (e.g., downlink reference signals) transmitted from each cell (e.g., candidate cell / serving cell). A method in which the UE obtains the TA for the candidate cell based on DL signals transmitted from one or more cells may be called UE-based TA measurement.

[0165] In the UE-based TA measurement, the downlink reference signal may be a predetermined DL signal (e.g., a synchronization signal block (e.g., SSB) / CSI-RS, etc.). For example, the UE may measure the difference / difference in reception timing of DL signals from multiple cells (or two cells) and obtain the TA of a candidate cell.

[0166] The multiple cells may include a reference cell (e.g., a serving cell). In this case, the UE may calculate the TA required for the candidate cell based on the reception timing of the reference cell (and the TA value of the reference cell) and the timing difference (e.g., T) between the reference cell and the candidate cell. The UE may obtain the TA of the candidate cell using a timing advance command (TAC) transmitted from the serving cell.

[0167] (analysis) In CLTM, the same specifications as those of LTM in Rel. 18 can be defined for both RACH-less LTM and RACH-based LTM.

[0168] Here, for example, when RACH-less LTM is performed for CLTM, the UE needs to obtain TA for the target cell before triggering CLTM.

[0169] Therefore, it is necessary to clarify how a UE obtains a TA for a target cell and the related provisions for this method.

[0170] As such, the rules regarding CLTM are not sufficiently clear. Without these rules, it is not possible to achieve lower latency communications, which may hinder improvements in communication quality and throughput.

[0171] Therefore, the present inventors came up with a method for solving these problems.

[0172] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Wireless communication methods according to the embodiments may be applied independently or in combination.

[0173] (Various reading changes) In this disclosure, words enclosed in "()" in a sentence may indicate an explanation of the immediately preceding wording (for example, an explanation of spelling), a paraphrase, a specific example, a supplementary explanation, etc. Also, in this disclosure, words enclosed in "[ ]" in a sentence may be interpreted including the meaning of the entire sentence, or may be interpreted excluding the meaning of the entire sentence (ignoring the meaning of the entire sentence). Note that "()" and "[ ]" may also be used for purposes / meanings other than those mentioned above.

[0174] In the present disclosure, "A / B" and "at least one of A and B" may be interpreted interchangeably. Also, in the present disclosure, "A / B / C" may mean "at least one of A, B, and C."

[0175] In the present disclosure, terms such as notify, activate, deactivate, indicate (or indicate), select, configure, update, and determine may be interchangeable. In the present disclosure, terms such as support, control, controllable, operate, and operate may be interchangeable.

[0176] In the present disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher layer parameters, fields, information elements (IEs), settings, etc. may be interchangeable. In the present disclosure, Medium Access Control (MAC) control elements (CEs), update commands, activation / deactivation commands, etc. may be interchangeable.

[0177] In the present disclosure, the higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, other messages (e.g., messages from the core network such as positioning protocol (e.g., NR Positioning Protocol A (NRPPa) / LTE Positioning Protocol (LPP)) messages), or a combination thereof.

[0178] In the present disclosure, MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. Broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

[0179] In the present disclosure, physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and the like.

[0180] In this disclosure, the terms drop, abort, cancel, puncture, rate match, postpone, do not transmit, etc. may be read interchangeably.

[0181] In the present disclosure, the terms index, identifier (ID), indicator, resource ID, etc. may be interchangeable. In the present disclosure, the terms sequence, list, set, group, cluster, subset, pool, etc. may be interchangeable.

[0182] In this disclosure, the terms panel, UE panel, panel group, beam, beam group, precoder, Uplink (UL) transmitting entity, Transmission / Reception Point (TRP), base station, Spatial Relation Information (SRI), spatial relation, SRS Resource Indicator (SRI), Control Resource Set (CORESET), Physical Downlink Shared Channel (PDSCH), Codeword (CW), Transport Block (TB), Reference Signal (RS), antenna port (e.g., Demodulation Reference Signal (DMRS) port), antenna port group (e.g., DMRS port group), group (e.g., spatial relation group, Code Division Multiplexing (CDM) group, reference signal group, CORESET group, Physical Uplink Control Channel (PUCCH) group, PUCCH resource group), resource (e.g., reference signal resource, SRS resource), resource set (e.g., reference signal resource set), CORESET pool, downlink Transmission Configuration Indication state (TCI state) (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, Quasi-Co-Location (QCL), QCL assumption, etc. may be read as interchangeable.

[0183] In the present disclosure, base station, gNB, and network (NW) may be interpreted as interchangeable.

[0184] In the present disclosure, cell group, serving cell group, master cell group (MCG), and secondary cell group (SCG) may be interchangeable. L1 / L2, L1 / L2 signaling, and DCI / MAC CE may be interchangeable. A serving cell may be replaced with a cell that transmits a PDSCH. A candidate cell may refer to a cell that is a candidate to become a serving cell through L1 / L2 inter-cell mobility. L1L2-triggered mobility (LTM) and L1 / L2 inter-cell mobility may be interchangeable.

[0185] In the present disclosure, the terms cell, PCI, serving cell, source serving cell, source cell, CC, BWP, BWP within CC, and band may be interchangeable. In the present disclosure, the terms cell, PCI, cell with additional PCI, additional cell, other cell, non-serving cell, cell with a different PCI, candidate cell, candidate serving cell, cell with a PCI different from the PCI of the current serving cell, another serving cell, and target cell may be interchangeable. A target cell may be a cell selected from multiple candidate cells. In the present disclosure, the terms switch, change, and update may be interchangeable. A serving cell may be interchangeable with a serving cell before a switch or a serving cell after a switch.

[0186] In the present disclosure, [for Rel. 19] event-based beam reporting, event-triggered beam reporting, UE-triggered beam reporting, UE-initiated beam reporting, event-triggered reporting / measurement, and UE-initiated beam management (UEIBM) may be read interchangeably.

[0187] In this disclosure, the event-triggered [beam] report may be interchangeably referred to as a beam report, a CSI report, an L1-RSRP beam report, or an L1-SINR beam report. These reports may also be simply referred to as reports.

[0188] In this disclosure, CSI reporting and CSI reporting for LTM in Rel. 18 may be read interchangeably.

[0189] In this disclosure, terms such as table, mapping, association, list, format, content, report, etc. may be read interchangeably.

[0190] In the present disclosure, (new) MAC CE, UCI, cell switch command, beam switch command, beam report MAC CE, and cell switch MAC CE may be read interchangeably.

[0191] In the present disclosure, the terms report, resource for report, and resource may be interchangeable. For example, a first resource and a first report may be interchangeable, and a second resource and a second report may be interchangeable.

[0192] In the present disclosure, the number of beams and the number of resources may be read interchangeably.

[0193] In the present disclosure, serving may be interchangeably read as serving beam / serving cell / SpCell.

[0194] In the present disclosure, neighbor may be interchangeably read as a beam / cell other than the serving beam / serving cell / SpCell / SCell.

[0195] In this disclosure, the pair of RS index and L1-RSRP / SINR may be referred to as an L1 measurement report, i.e., the L1 measurement report may include the pair of RS index and L1-RSRP / SINR.

[0196] In the present disclosure, candidate cells, target cells, neighboring cells, cells, etc. may be read interchangeably.

[0197] In the present disclosure, the occurrence of an event and the satisfaction of the conditions for the event may be read interchangeably.

[0198] In this disclosure, beam, RS, and [L1 / L3] measurement results may be interpreted interchangeably.

[0199] In this disclosure, the RS to be measured may be a QCL source RS in an active TCI state / indicated TCI state.

[0200] In the present disclosure, the spatial domain filter, the time domain filter, and the domain filter may be read interchangeably.

[0201] In this disclosure, NW / BS / gNB may be interpreted as interchangeable.

[0202] In the present disclosure, the current beam / new beam may correspond to at least one of an indicated TCI state, an indicated TCI state, an active TCI state, an activated TCI state, a configured TCI state, a configured TCI state, and an RS configured in RRC.

[0203] In the present disclosure, the terms indicated TCI state, active TCI state, activated TCI state, configured TCI state, configured TCI state, and RS configured in RRC may be read interchangeably.

[0204] In the present disclosure, the number of current beams / new beams may be one or more.

[0205] In the present disclosure, new beam / RS, candidate beam / RS, measurement beam / RS, measurement beam / RS, etc. may be read interchangeably.

[0206] In this disclosure, a new type of UCI (new UCI) may refer to a UCI that is transmitted in multiple bits (and multiple steps / parts).

[0207] Each embodiment of the present disclosure can be applied to any event.

[0208] In the present disclosure, L1-RSRP may be read interchangeably with L1-SINR.

[0209] In the present disclosure, the terms condition and threshold may be interpreted as interchangeable.

[0210] In the present disclosure, the filtered value (measured value: L1-RSRP), the filter value, and the L1-RSRP to which filtering by NW settings has been applied (NW-filtered L1-RSRP) may be read as interchangeable.

[0211] In the present disclosure, CC, carrier, cell, serving cell, frequency, frequency carrier, carrier frequency, etc. may be interchangeable. In the present disclosure, a multiple CC report may be interchangeable with a multiple event report.

[0212] In this disclosure, reporting a (current / measured) beam may mean reporting an RS index (e.g., CSI-RS resource indicator (CRI) / SSB resource indicator (SSBRI)) and measurement results (e.g., L1-RSRP / RSRQ / SINR) corresponding to the (current / measured) beam. In this disclosure, information about a beam may mean the RS index / measurement results corresponding to the beam.

[0213] In this disclosure, "current beam" may mean "current beam of the current serving cell" in mobility.

[0214] In the present disclosure, the terms beam, RS, RS resource, RS resource set, RS index, RS indicator, RS ID, etc. may be interchangeable. In the present disclosure, the terms RS resource set, subset of RS resources, subset of RS, etc. may be interchangeable.

[0215] In the present disclosure, the type of CSI reporting may be periodic, semi-persistent, or aperiodic, i.e., the present disclosure is applicable to any type of CSI reporting.

[0216] In the present disclosure, multiplexing (multiplexing / being multiplexed) and mapping (mapping / being mapped) may be read interchangeably.

[0217] In the present disclosure, the multiple events may be any of the events described above (or a combination of multiple events).

[0218] In the present disclosure, handover, handover defined in Rel. 15, CHO, DAPS handover, LTM, CLTM, and cell switching may be read interchangeably.

[0219] In the present disclosure, the terms configuration, upper layer signaling, upper layer parameters, RRC parameters (which may simply be referred to as parameters), RRC configuration, etc. may be read interchangeably.

[0220] (Wireless communication method) The UE may execute / control CLTM and related operations by applying the present disclosure (the various provisions described above and the following embodiments). The NW / BS / gNB may provide / transmit to the UE settings / instructions, etc., for the UE to realize the control. Furthermore, the NW / BS / gNB may execute various controls necessary to receive information, etc., transmitted from the UE.

[0221] The present disclosure is applicable to each use case of MIMO / mobility. A beam report for MIMO may be referred to as a UEIBR, and a beam report for mobility may be referred to as an event-triggered beam report.

[0222] In the present disclosure, each embodiment / option may be applied alone or in combination with other embodiments / options.

[0223] This disclosure clarifies how to obtain TA in CLTM and the related rules (e.g., how to determine RACH-less LTM / RACH-based LTM). The UE can appropriately control CLTM based on these rules. As a result, it is possible to achieve communication with lower latency and improve communication quality and throughput.

[0224] First Embodiment The first embodiment relates to TA acquisition in CLTM.

[0225] <<Aspect 1-1>> To perform RACH-less LTM, the UE needs to obtain the TA for the target cell before triggering CLTM (before receiving the cell switch command).

[0226] The following options can be exemplified as operations that can be applied in CLTM: That is, the UE may perform at least one operation of the following options: Figure 9 is a diagram illustrating an example of a TA acquisition method.

[0227] (Opt1) PDCCH ordered RACH with RAR.

[0228] That is, the UE may acquire the TA using the RACH. Information about the TA of the target cell (e.g., the TA value) may be included in a response signal (e.g., an RAR) of the RACH.

[0229] A PDCCH order (e.g., DCI format 1_0) may be used as the PDCCH order for the LTM of Rel.18.

[0230] The method of identifying / distinguishing / determining a PDCCH order RACH with (having) RAR and a PDCCH order RACH without (having) RAR can apply at least one of the following options.

[0231] ((Opt1-A)) A distinguishing one-bit indication may be added, for example a bit value of "1" may indicate a PDCCH ordered RACH with RAR and a bit value of "0" may indicate a PDCCH ordered RACH without RAR, or vice versa.

[0232] ((Opt1-B)) Whether or not the RAR is included may be indicated by a specific field value in the PDCCH order, and the correspondence between the field values ​​may be the same as that in Opt1-A.

[0233] ((Opt1-C)) Whether or not RAR is involved may be identified by the configuration (RRC parameters) for the candidate cell indicated by the cell indicator field in the PDCCH order.

[0234] For example, if CLTM is configured for a candidate cell, the operation of Opt2 described below may be triggered.

[0235] In Opt1, the UE may ignore the PRACH transmission (retransmission) indicator field.

[0236] The RAR may be received in a candidate cell indicated by the cell indicator field of the PDCCH order.

[0237] In Opt1, power ramping may be performed in the candidate cell, i.e., the UE may perform power ramping in the candidate cell.

[0238] (Opt2) PDCCH ordered RACH without RAR and new DL signaling indicating TAC.

[0239] That is, the UE may acquire the TA using the RACH. The UE may acquire the TA of the target cell by receiving new DL signaling from the base station indicating the TAC.

[0240] The same methods as those of Opt1-A to Opt1-C described above can be applied to the method of identifying / distinguishing / determining between the PDCCH order RACH without RAR for LTM for Rel.18 and this option (Opt2).

[0241] More specifically, the following Opt2-A to Opt2-C can be exemplified. Opt2-A to Opt2-C correspond to the above-mentioned Opt1-A to Opt1-C (whether or not Opt1-A to Opt1-C include RAR may be interpreted as whether or not Opt2-A to Opt2-C are for Rel. 18).

[0242] ((Opt2-A)) A one-bit indication may be added for identification, for example, a bit value of "1" may indicate Opt2 and a bit value of "0" may indicate a PDCCH-ordered RACH without RAR for LTM for Rel.18, or vice versa.

[0243] ((Opt2-B)) Whether the PDCCH order is a RACH without RAR for LTM for Rel. 18 or Opt2 may be indicated by a specific field value in the PDCCH order. The correspondence between the field values ​​may be the same as Opt1-A.

[0244] ((Opt2-C)) Whether the PDCCH order is RACH without RAR for LTM for Rel. 18 or Opt2 may be identified by the configuration (RRC parameters) for the candidate cell indicated by the cell indicator field in the PDCCH order.

[0245] New DL signaling indicating the TAC may be received at the serving cell.

[0246] In Opt2, power ramping may or may not be performed. If power ramping is performed, a new window / timer / counter may be used. That is, the UE may or may not perform power ramping. If the UE performs power ramping, it may use a new window / timer / counter.

[0247] (Opt3) UE-based TA measurements.

[0248] That is, the UE may obtain the target TA by measuring the TA itself.

[0249] For candidate cells for which CLTM is configured, UE-based TA measurements must always be configured.

[0250] When UE-based TA measurements are used, the trigger conditions for CLTM may include whether TA for the target cell has been obtained by UE-based TA measurements, in addition to conditions for events related to the quality of the beam / candidate cell.

[0251] The methods Opt1 to Opt3 described above may be used / applied [only] to CLTM.

[0252] <<Aspect 1-2>> The RACH resource for the RACH-based LTM after receiving the cell switch command may be different between UEs. Therefore, in order to save the RACH resource, the NW is assumed to configure either the RACH resource for the early RACH or the RACH resource for the RACH-based LTM after receiving the cell switch command for each UE / candidate cell.

[0253] Here, the RACH resource may be a RACH resource that is subject to (configured by) a specific parameter related to reconfiguration and synchronization (for example, ReconfigWithSync).

[0254] In view of the above, when either Opt1 or Opt2 in aspect 1-1 is applied, at least one of the following options may be applied as a network implementation (see FIG. 9): The UE may determine / judge whether to perform RACH-less LTM or RACH-based LTM based on at least one of the following options.

[0255] (Opt1) Only RACH resources for early RACH may be configured. That is, the NW may configure only RACH resources for early RACH. In this case, the UE may always perform only RACH-less LTM. The UE does not need to expect / assume that RACH resources for RACH-based LTM will be configured.

[0256] (Opt2) Only RACH resources for the RACH-based LTM after receiving the cell switch command may be configured. That is, the NW may configure only RACH resources for the RACH-based LTM. In this case, the UE may always perform only RACH-based LTM. The UE does not need to expect / assume that RACH resources for the early RACH will be configured.

[0257] (Opt3) Both the RACH resource for the early RACH and the RACH resource for the RACH-based LTM after receiving the cell switch command may be configured. That is, the NW may configure both the RACH resource for the early RACH and the RACH-based LTM after receiving the cell switch command. The UE may select and apply / execute either the RACH-less LTM or the RACH-based LTM.

[0258] <<Aspects 1-3>> However, certain parameters related to reconfiguration and synchronization (reconfiguration with synchronization), such as ReconfigWithSync, are decoded after receiving a cell switch command, so there may be cases where the UE cannot recognize whether RACH resources for RACH-based LTM are configured after receiving a cell switch command.

[0259] In this case, it is necessary for the UE to clarify how to recognize / identify Opt1 to Opt3 in aspect 1-2.

[0260] Therefore, the following options may apply: In addition to (in addition to) aspects 1-2, the UE may determine / judge whether to perform RACH-less LTM or RACH-based LTM based on at least one of the following options:

[0261] (OptA) The UE may determine whether to perform RACH-less LTM or RACH-based LTM based on whether RACH resources for the early RACH are configured. For example, the UE may perform (or decide to perform) RACH-less LTM if RACH resources for the early RACH are configured. On the other hand, the UE may perform (or decide to perform) RACH-based LTM if RACH resources for the early RACH are not configured.

[0262] Note that Opt3 in aspect 1-2 does not need to be expected / assumed before the cell switching command is received.

[0263] (OptB) The UE may determine / judge which of the RACH-less LTM and RACH-based LTM to execute based on explicit RRC parameters that can be set for each candidate cell / UE.

[0264] For example, when the parameter value is "0", it may mean that the RACH resource for RACH-based LTM is not set after receiving the cell switch command (i.e., execute RACH-less LTM). On the other hand, when the parameter value is "1", it may mean that the RACH resource for RACH-based LTM is set after receiving the cell switch command (i.e., execute RACH-based LTM).

[0265] According to this embodiment, it becomes clear for the UE to obtain the TA in the CLTM and the related regulations (e.g., the method for judging RACH-less LTM / RACH-based LTM).

[0266] <Supplement> <<Notification of Information to UE>> The notification of any information from the [network (Network (NW)) (e.g., base station (Base Station (BS)))] to the UE in the above embodiment (in other words, the reception of any information from the BS by the UE) may be performed using physical layer signaling (e.g., DCI), upper layer signaling (e.g., RRC signaling, MAC CE), specific signals / channels (e.g., PDCCH, PDSCH, reference signal), or a combination thereof.

[0267] When the above notification is performed by MAC CE, the MAC CE may be identified by including a new logical channel ID (Logical Channel ID (LCID)) that is not defined in the existing standard in the MAC sub-header.

[0268] When the above notification is performed by DCI, the above notification may be performed by a specific field of the DCI, a Radio Network Temporary Identifier (RNTI) used for scrambling Cyclic Redundancy Check (CRC) bits assigned to the DCI, a format of the DCI, or the like.

[0269] Also, the notification of any information to the UE in the above-described embodiment may be performed periodically, semi-persistently, or aperiodically.

[0270] <<Notification of Information from UE>> The notification of any information from the UE to [NW] (in other words, the transmission / reporting of any information from the UE to the BS) in the above-described embodiment may be performed using physical layer signaling (e.g., UCI), upper layer signaling (e.g., RRC signaling, MAC CE), a specific signal / channel (e.g., PUCCH, PUSCH, PRACH, reference signal), or a combination thereof.

[0271] When the above notification is performed by MAC CE, the MAC CE may be identified by including a new LCID not defined in the existing standard in the MAC subheader.

[0272] When the above notification is performed by UCI, the above notification may be transmitted using PUCCH or PUSCH.

[0273] Also, the notification of any information from the UE in the above-described embodiment may be performed periodically, semi-persistently, or aperiodically.

[0274] <<Regarding Application of Each Embodiment>> In the UE / BS, specific (one or more) processes / operations / controls / assumptions / information regarding at least one of the above-described embodiments may be applied (used) when any one or a plurality of the following conditions are satisfied: Upper layer parameters indicating the above specific processing / operation / control / assumment / information are set. The specific processing / action / control / assumption / information is determined based on the relevant upper layer parameters. The above specific processes / actions / controls / assumptions / information are specified / activated / triggered by MAC CE / DCI / UCI / resources / channels / RS. Reporting or supporting specific UE capabilities indicating (or relating to) the above specific processes / actions / controls / assumptions / information. · The application of the above specific processing / action / control / assumption / information is judged based on specific conditions.

[0275] The specific UE capabilities may indicate at least one of the following: Supporting specific processing / operations / control / information for at least one of the above embodiments. Supporting the Rel.18 CSI reporting framework for LTM. Support MIMO / mobility (e.g. CLTM) for Rel.19 and later. Support MAC CE-based Event Triggered Beam Reporting (UEIBR).

[0276] Furthermore, the above-mentioned specific UE capability may be a capability that is applied across all frequencies (commonly regardless of frequency), or may be a capability for each frequency (e.g., one or a combination of a cell, band, band combination, BWP, component carrier, etc.), or may be a capability for each frequency range (e.g., Frequency Range 1 (FR1), FR2, FR3, FR4, FR5, FR2-1, FR2-2), or may be a capability for each subcarrier spacing (SubCarrier Spacing (SCS)), or may be a capability for each Feature Set (FS) or Feature Set Per Component-carrier (FSPC).

[0277] Furthermore, the specific UE capability may be a capability that is applied across all duplexing methods (commonly regardless of the duplexing method), or may be a capability for each duplexing method (for example, Time Division Duplex (TDD) or Frequency Division Duplex (FDD)).

[0278] If the above conditions are not met, the UE / BS may follow the behavior specified in existing 3GPP releases.

[0279] (Addendum) The following inventions are added regarding one embodiment of the present disclosure. [Appendix 1] a receiver for receiving a cell switch command that triggers conditional L1 / L2 triggered mobility (CLTM); a control unit that controls the CLTM based on the cell switching command, The terminal, wherein the control unit acquires a timing advance (TA) for the target cell by a specific method before triggering the CLTM. [Appendix 2] The terminal according to Supplementary Note 1, wherein the control unit acquires the TA by a method using a random access channel (RACH) or by terminal-based measurement. [Appendix 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein when the TA is obtained using a random access channel (RACH), at least one of a RACH resource for an early RACH and a RACH-based RACH resource is configured. [Appendix 4] The terminal according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the control unit determines whether to perform RACH-less LTM or RACH-based LTM based on specific conditions when acquiring the TA using a random access channel (RACH).

[0280] (wireless communication system) The configuration of a wireless communication system according to an embodiment of the present disclosure will be described below. In this wireless communication system, communication is performed using any one of the wireless communication methods according to the above embodiments of the present disclosure or a combination thereof.

[0281] 10 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 (which may be simply referred to as system 1) may be a system that realizes communication using Long Term Evolution (LTE), 5th generation mobile communication system New Radio (5G NR), or the like, which are specified by the Third Generation Partnership Project (3GPP).

[0282] The wireless communication system 1 may also support dual connectivity between multiple Radio Access Technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC may include dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), dual connectivity between NR and LTE (NR-E-UTRA Dual Connectivity (NE-DC)), etc.

[0283] In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (MN), and the NR base station (gNB) is the secondary node (SN). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

[0284] The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity in which both the MN and the SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

[0285] The wireless communication system 1 may include a base station 11 that forms a macrocell C1 with a relatively wide coverage, and base stations 12 (12a-12c) that are located within the macrocell C1 and form small cells C2 that are smaller than the macrocell C1. A user terminal 20 may be located within at least one of the cells. The location, number, shape, size, etc. of each cell and user terminal 20 are not limited to the embodiment shown in the figure. Hereinafter, when there is no need to distinguish between the base stations 11 and 12, they will be collectively referred to as base station 10.

[0286] The wireless communication system 1 may utilize Multi Input Multi Output (MIMO). For example, one cell may be formed by one antenna / base station 10, or may be formed by multiple antennas / base stations 10. One [virtual] cell (which may be called, for example, a super cell) may be composed of multiple [virtual] cells (which may be called, for example, sub-cells). A super cell may correspond to a cell whose physical range is fixed, and a sub-cell may correspond to a cell whose physical range varies semi-statically / dynamically. In this case, the wireless communication system 1 may be called a cell-free system.

[0287] The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using multiple component carriers (CC) and dual connectivity (DC).

[0288] Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). The macro cell C1 may be included in FR1, and the small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHz), and FR2 may be a frequency band above 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may be a frequency band higher than FR2.

[0289] Furthermore, the user terminal 20 may perform communication using at least one of Time Division Duplex (TDD) and Frequency Division Duplex (FDD) in each CC.

[0290] The multiple base stations 10 may be connected by wire (for example, optical fiber conforming to the Common Public Radio Interface (CPRI), an X2 / Xn interface, etc.) or wirelessly (for example, NR communication). For example, when NR communication is used as a backhaul between the base stations 11 and 12, the base station 11 corresponding to the upper station may be called an Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to the relay station (relay) may be called an IAB node.

[0291] The base station 10 may be connected to the core network 30 directly or via another base station 10. The core network 30 may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), a Next Generation Core (NGC), and the like.

[0292] The core network 30 may include network functions (NFs) such as a User Plane Function (UPF), an Access and Mobility management Function (AMF), a Session Management Function (SMF), a Unified Data Management (UDM), an Application Function (AF), a Data Network (DN), a Location Management Function (LMF), and an Operation, Administration and Maintenance (Management) (OAM). Note that a single network node may provide multiple functions. Furthermore, communication with an external network (e.g., the Internet) may be performed via the DN.

[0293] The user terminal 20 may be a terminal compatible with at least one of communication methods such as LTE, LTE-A, and 5G.

[0294] An Orthogonal Frequency Division Multiplexing (OFDM)-based radio access scheme may be used in the radio communication system 1. For example, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), or the like may be used in at least one of the downlink (DL) and uplink (UL).

[0295] The radio access scheme may also be called a waveform. Note that in the wireless communication system 1, other radio access schemes (for example, other single-carrier transmission schemes, other multi-carrier transmission schemes) may be used as the UL and DL radio access schemes.

[0296] In the wireless communication system 1, a downlink shared channel (Physical Downlink Shared Channel (PDSCH)) shared by each user terminal 20, a broadcast channel (Physical Broadcast Channel (PBCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), etc. may be used as the downlink channel.

[0297] Furthermore, in the wireless communication system 1, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), etc. may be used as an uplink channel.

[0298] The PDSCH transmits user data, higher layer control information, System Information Block (SIB), etc. The PUSCH may transmit user data, higher layer control information, etc. Furthermore, the PBCH may transmit Master Information Block (MIB).

[0299] Lower layer control information may be transmitted by the PDCCH. The lower layer control information may include, for example, Downlink Control Information (DCI) including scheduling information for at least one of the PDSCH and the PUSCH.

[0300] Note that the DCI for scheduling the PDSCH may be referred to as a DL assignment, a DL DCI, etc., and the DCI for scheduling the PUSCH may be referred to as an UL grant, a UL DCI, etc. Note that the PDSCH may be interpreted as DL data, and the PUSCH may be interpreted as UL data.

[0301] A control resource set (CORESET) and a search space may be used to detect the PDCCH. The CORESET corresponds to resources to search for DCI. The search space corresponds to a search region and a search method for PDCCH candidates. One CORESET may be associated with one or more search spaces. The UE may monitor a CORESET associated with a certain search space based on the search space configuration.

[0302] One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be called a search space set. Note that the terms "search space," "search space set," "search space setting," "search space set setting," "CORESET," "CORESET setting," etc. in the present disclosure may be read interchangeably.

[0303] The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), acknowledgement information (which may be called, for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR). The PRACH may transmit a random access preamble for establishing a connection with a cell.

[0304] In the present disclosure, downlink, uplink, etc. may be expressed without adding "link." Also, various channels may be expressed without adding "Physical" to the beginning.

[0305] In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), etc. may be transmitted. In the wireless communication system 1, a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), etc. may be transmitted as DL-RS.

[0306] The synchronization signal may be, for example, at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). A signal block including the SS (PSS, SSS) and the PBCH (and DMRS for the PBCH) may be referred to as an SS / PBCH block, an SS Block (SSB), or the like. Note that the SS, SSB, and the like may also be referred to as reference signals.

[0307] Furthermore, in the wireless communication system 1, a sounding reference signal (SRS), a demodulation reference signal (DMRS), etc. may be transmitted as an uplink reference signal (UL-RS). Note that the DMRS may also be called a user equipment-specific reference signal (UE-specific reference signal).

[0308] (base station) 11 is a diagram showing an example of the configuration of a base station according to an embodiment. The base station 10 includes a control unit 110, a transceiver unit 120, a transceiver antenna 130, and a transmission line interface 140. Note that the base station may include one or more of each of the control unit 110, the transceiver unit 120, the transceiver antenna 130, and the transmission line interface 140.

[0309] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and it may be assumed that the base station 10 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0310] The control unit 110 performs overall control of the base station 10. The control unit 110 can be configured from a controller, a control circuit, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0311] The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may control transmission and reception using the transceiver unit 120, the transceiver antenna 130, and the transmission path interface 140, measurement, etc. The control unit 110 may generate data to be transmitted as signals, control information, sequences, etc., and transfer them to the transceiver unit 120. The control unit 110 may perform call processing (setting up, releasing, etc.) of communication channels, status management of the base station 10, management of radio resources, etc.

[0312] The transceiver unit 120 may include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may include a transmission processing unit 1211 and a reception processing unit 1212. The transceiver unit 120 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0313] The transmitting / receiving unit 120 may be configured as an integrated transmitting / receiving unit, or may be composed of a transmitting unit and a receiving unit. The transmitting unit may be composed of a transmission processing unit 1211 and an RF unit 122. The receiving unit may be composed of a reception processing unit 1212, an RF unit 122, and a measurement unit 123.

[0314] The transmitting and receiving antenna 130 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure pertains, such as an array antenna.

[0315] The transceiver 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 120 may receive the above-mentioned uplink channel, uplink reference signal, etc.

[0316] The transceiver 120 may form at least one of a transmission beam and a reception beam using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), or the like.

[0317] The transceiver 120 (transmission processing unit 1211) may perform Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (e.g., RLC retransmission control), Medium Access Control (MAC) layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 110, and generate a bit string to be transmitted.

[0318] The transceiver 120 (transmission processor 1211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, Discrete Fourier Transform (DFT) processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0319] The transmitting / receiving unit 120 (RF unit 122) may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal, and transmit the radio frequency band signal via the transmitting / receiving antenna .

[0320] On the other hand, the transmitting / receiving unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna .

[0321] The transceiver 120 (reception processing unit 1212) may apply reception processing such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, thereby acquiring user data, etc.

[0322] The transceiver 120 (measurement unit 123) may perform measurements on the received signal. For example, the measurement unit 123 may perform Radio Resource Management (RRM) measurements, Channel State Information (CSI) measurements, etc. based on the received signal. The measurement unit 123 may measure received power (e.g., Reference Signal Received Power (RSRP)), received quality (e.g., Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)), signal strength (e.g., Received Signal Strength Indicator (RSSI)), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 110.

[0323] The transmission path interface 140 may transmit and receive signals (backhaul signaling) between devices included in the core network 30 (e.g., network nodes providing NFs), other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0324] The transmitting section and receiving section of the base station 10 in the present disclosure may be configured by at least one of the transmitting / receiving section 120, the transmitting / receiving antenna 130, and the transmission path interface 140.

[0325] The base station 10 may be separated into three elements: a radio unit (RU), a distributed unit (DU), and a central unit (CU). For example, the RU may perform RF processing (digital beamforming, digital-to-analog conversion, analog beamforming, etc.) and lower-level functions of the physical layer (precoding, IFFT, FFT, etc.). The DU may perform higher-level functions of the physical layer (coding to resource element mapping, etc.), MAC layer functions, and RLC layer functions. The CU may perform PDCP layer, Service Data Adaptation Protocol (SDAP) layer, and RRC layer functions.

[0326] In the present disclosure, the base station 10 may include a single device that implements all of the functions of the RU, DU, and CU, or may include multiple devices that each implement some of the functions of the RU, DU, and CU and are connected to each other. In the present disclosure, the base station 10 may be interchangeably read as RU / DU / CU.

[0327] The transceiver 120 may transmit a cell switch command that triggers conditional L1 / L2 triggered mobility (CLTM). The controller 110 may control the CLTM based on the cell switch command. Before triggering the CLTM, the controller 110 may control transmission of a configuration related to a specific method for the terminal to acquire a timing advance (TA) for a target cell.

[0328] (user terminal) 12 is a diagram showing an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transceiver unit 220, and a transceiver antenna 230. Note that the user terminal 20 may include one or more of each of the control unit 210, the transceiver unit 220, and the transceiver antenna 230.

[0329] Note that this example mainly shows functional blocks of the characteristic parts of the present embodiment, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0330] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be configured from a controller, a control circuit, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0331] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may also control transmission and reception, measurement, etc. using the transceiver unit 220 and the transceiver antenna 230. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transceiver unit 220.

[0332] The transceiver unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transceiver unit 220 may be configured from a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0333] The transmitting / receiving unit 220 may be configured as an integrated transmitting / receiving unit, or may be composed of a transmitting unit and a receiving unit. The transmitting unit may be composed of a transmission processing unit 2211 and an RF unit 222. The receiving unit may be composed of a reception processing unit 2212, an RF unit 222, and a measurement unit 223.

[0334] The transmitting / receiving antenna 230 can be configured as an antenna described based on common understanding in the technical field to which the present disclosure pertains, such as an array antenna.

[0335] The transceiver 220 may receive the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 220 may transmit the above-mentioned uplink channel, uplink reference signal, etc.

[0336] The transceiver 220 may form at least one of a transmission beam and a reception beam using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), or the like.

[0337] The transceiver 220 (transmission processing unit 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 210, and generate a bit string to be transmitted.

[0338] The transceiver 220 (transmission processor 2211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, DFT processing (if necessary), IFFT processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0339] Whether or not to apply DFT processing may be based on the setting of transform precoding. When transform precoding is enabled for a certain channel (e.g., PUSCH), the transceiver unit 220 (transmission processing unit 2211) may perform DFT processing as the transmission processing to transmit the channel using a DFT-s-OFDM waveform, and when transform precoding is not enabled, the transceiver unit 220 may not perform DFT processing as the transmission processing.

[0340] The transmitting / receiving unit 220 (RF unit 222) may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal, and transmit the radio frequency band signal via the transmitting / receiving antenna 230.

[0341] On the other hand, the transmitting / receiving unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna 230.

[0342] The transceiver 220 (reception processing unit 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal to acquire user data, etc.

[0343] The transceiver 220 (measurement unit 223) may perform measurements on the received signal. For example, the measurement unit 223 may perform RRM measurement, CSI measurement, etc. based on the received signal. The measurement unit 223 may measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 210.

[0344] The measurement unit 223 may derive channel measurements for CSI calculation based on the channel measurement resources. The channel measurement resources may be, for example, non-zero power (NZP) CSI-RS resources. The measurement unit 223 may also derive interference measurements for CSI calculation based on the interference measurement resources. The interference measurement resources may be at least one of an NZP CSI-RS resource for interference measurement, a CSI-Interference Measurement (IM) resource, etc. Note that CSI-IM may be referred to as CSI-Interference Management (IM) or may be interchangeably read as Zero Power (ZP) CSI-RS. Note that in the present disclosure, CSI-RS, NZP CSI-RS, ZP CSI-RS, CSI-IM, CSI-SSB, etc. may be interchangeably read as interchangeable.

[0345] The transmitting section and receiving section of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving section 220 and the transmitting / receiving antenna 230.

[0346] The control unit 210 may perform at least part of the processing of the control unit in the above appendix.

[0347] The transceiver unit 220 may perform at least part of the processing of the transmitter / receiver unit in the above appendix.

[0348] When the TA is obtained using a random access channel (RACH), at least one of an early RACH resource and a RACH-based RACH resource may be configured.

[0349] (Hardware configuration) The block diagrams used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wires, wirelessly, etc.) and these multiple devices. The functional block may also be realized by combining the single device or multiple devices with software.

[0350] Here, the functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission may be called a transmitting unit, transmitter, etc. As mentioned above, the implementation method of each is not particularly limited.

[0351] For example, a base station, a user terminal, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 13 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. The above-described base station 10 and user terminal 20 may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0352] In this disclosure, terms such as apparatus, circuit, device, section, unit, etc. may be read interchangeably. The hardware configurations of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the drawings, or may be configured to exclude some of the devices.

[0353] For example, although only one processor 1001 is shown, there may be multiple processors. Furthermore, processing may be performed by one processor, or processing may be performed by two or more processors simultaneously, serially, or in other ways. Furthermore, processor 1001 may be implemented by one or more chips.

[0354] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading predetermined software (programs) onto hardware such as a processor 1001 and a memory 1002, causing the processor 1001 to perform calculations, control communication via the communication device 1004, and control at least one of reading and writing data in the memory 1002 and the storage 1003.

[0355] The processor 1001, for example, runs an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, at least a part of the above-mentioned control unit 110 (210), transmission / reception unit 120 (220), etc. may be realized by the processor 1001.

[0356] The processor 1001 also reads programs (program codes), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 110 (210) may be realized by a control program stored in the memory 1002 and running on the processor 1001, and the other functional blocks may be realized in a similar manner.

[0357] The memory 1002 is a computer-readable recording medium and may be configured by at least one of, for example, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), or other suitable storage medium. The memory 1002 may also be referred to as a register, a cache, a main memory, or the like. The memory 1002 may store executable programs (program codes), software modules, and the like for implementing a wireless communication method according to an embodiment of the present disclosure.

[0358] Storage 1003 is a computer-readable recording medium and may be constituted by at least one of, for example, a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disc (e.g., a Compact Disc ROM (CD-ROM)), a digital versatile disc, a Blu-ray disc), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, stick, key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be referred to as a secondary storage device.

[0359] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, or a communication module. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the above-mentioned transmission / reception unit 120 (220), transmission / reception antenna 130 (230), etc. may be realized by the communication device 1004. The transmission / reception unit 120 (220) may be implemented as a transmission unit 120a (220a) and a reception unit 120b (220b) that are physically or logically separated.

[0360] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (for example, a display, a speaker, a light emitting diode (LED) lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may be integrated into one device (for example, a touch panel).

[0361] Furthermore, each device, such as the processor 1001 and the memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0362] Furthermore, the base station 10 and the user terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized using such hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0363] Note that the devices included in the core network 30 (for example, network nodes that provide NFs) may also be realized by the above-described functional block / hardware configuration.

[0364] (Variation) Note that terms explained in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, a channel, a symbol, and a signal (signal or signaling) may be interchangeable. A signal may also be a message. A reference signal may be abbreviated as RS, and may also be called a pilot, pilot signal, etc. depending on the applicable standard. A component carrier (CC) may also be called a cell, frequency carrier, carrier frequency, etc.

[0365] A radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting a radio frame may be called a subframe. Furthermore, a subframe may be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0366] Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, and may indicate at least one of, for example, a subcarrier spacing (SCS), a bandwidth, a symbol length, a cyclic prefix length, a transmission time interval (TTI), the number of symbols per TTI, a radio frame structure, a specific filtering process performed by a transceiver in the frequency domain, and a specific windowing process performed by a transceiver in the time domain.

[0367] A slot may be composed of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol), and may be a time unit based on numerology.

[0368] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (PUSCH) mapping type B.

[0369] A radio frame, a subframe, a slot, a minislot, and a symbol all represent time units for transmitting signals. The radio frame, the subframe, the slot, the minislot, and the symbol may be referred to by other names corresponding to the radio frame, the subframe, the slot, the minislot, and the symbol. Note that the time units such as a frame, a subframe, a slot, a minislot, and a symbol in the present disclosure may be interchangeable.

[0370] For example, one subframe may be referred to as a TTI, or multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as a TTI. That is, at least one of a subframe and a TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc., instead of a subframe.

[0371] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. However, the definition of TTI is not limited to this.

[0372] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0373] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0374] A TTI having a time length of 1 ms may be called a regular TTI (TTI in 3GPP Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0375] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0376] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may also be determined based on numerology.

[0377] In addition, an RB may include one or more symbols in the time domain and may have a length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0378] Note that one or more RBs may also be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0379] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0380] A Bandwidth Part (BWP), which may also be referred to as a fractional bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a common reference point of the carrier. PRBs may be defined in a given BWP and numbered within that BWP.

[0381] The BWP may include an UL BWP (a BWP for UL) and a DL BWP (a BWP for DL). One or more BWPs may be configured for a UE within one carrier.

[0382] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0383] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0384] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by a predetermined index.

[0385] The names used for parameters and the like in this disclosure are not intended to be limiting in any way. Furthermore, the mathematical expressions and the like using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0386] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0387] Furthermore, information, signals, etc. may be output from a higher layer to a lower layer and / or from a lower layer to a higher layer. Information, signals, etc. may be input / output via multiple network nodes.

[0388] Input and output information, signals, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information, signals, etc. may be overwritten, updated, or added. Output information, signals, etc. may be deleted. Input information, signals, etc. may be transmitted to another device.

[0389] With respect to any information (e.g., variables, constants, parameters) described in the present disclosure, even if not specifically stated in the above embodiments, any first device (e.g., UE / base station) may notify any second device (e.g., base station / UE) of information indicating / identifying (or relating to) the value of the any information.

[0390] Notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, notification of information in the present disclosure may be performed by physical layer signaling (e.g., Downlink Control Information (DCI) and Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB) and System Information Block (SIB)), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0391] Note that the physical layer signaling may be called Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), etc. Furthermore, the RRC signaling may be called an RRC message, such as an RRC connection setup message or an RRC connection reconfiguration message. Furthermore, the MAC signaling may be notified using, for example, a MAC Control Element (CE).

[0392] Furthermore, notification of specified information (e.g., notification that "it is X") is not limited to explicit notification, but may be made implicitly (e.g., by not notifying the specified information or by notifying other information).

[0393] The determination may be made by a value represented by one bit (0 or 1), by a Boolean value represented by true or false, or by a comparison of numerical values ​​(e.g., comparison with a predetermined value).

[0394] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0395] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0396] As used in this disclosure, the terms "system" and "network" may be used interchangeably. A "network" may refer to devices included in the network (e.g., base stations).

[0397] In the present disclosure, terms such as "precoding," "precoder," "weight (precoding weight)," "Quasi-Co-Location (QCL)," "Transmission Configuration Indication state (TCI state)," "spatial relation," "spatial domain filter," "transmit power," "phase rotation," "antenna port," "layer," "number of layers," "rank," "resource," "resource set," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," "UE panel," "transmitting entity," "receiving entity," etc. may be used interchangeably.

[0398] In the present disclosure, the term "antenna port" may be interchangeably read as an antenna port for any signal / channel (e.g., a demodulation reference signal (DMRS) port). In the present disclosure, the term "resource" may be interchangeably read as a resource for any signal / channel (e.g., a reference signal resource, an SRS resource, etc.). The resource may include time / frequency / code / space / power resources. The spatial domain transmission filter may include at least one of a spatial domain transmission filter and a spatial domain reception filter.

[0399] The group may include, for example, at least one of a spatial relationship group, a Code Division Multiplexing (CDM) group, a Reference Signal (RS) group, a Control Resource Set (CORESET) group, a PUCCH group, an antenna port group (e.g., a DMRS port group), a layer group, a resource group, a beam group, an antenna group, a panel group, and the like.

[0400] In addition, in the present disclosure, beam, SRS Resource Indicator (SRI), CORESET, CORESET pool, PDSCH, PUSCH, codeword (CW), transport block (TB), RS, etc. may be read as interchangeable terms.

[0401] In addition, in the present disclosure, the terms TCI state, downlink TCI state (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, joint TCI state, etc. may be read interchangeably.

[0402] Furthermore, in this disclosure, terms such as "QCL," "QCL assumptions," "QCL relationships," "QCL type information," "QCL properties," "specific QCL type (e.g., Type A, Type D) properties," and "specific QCL type (e.g., Type A, Type D)" may be interchangeable.

[0403] In this disclosure, terms such as index, identifier (ID), indicator, indication, and resource ID may be interchangeable. In this disclosure, terms such as sequence, list, set, group, cluster, and subset may be interchangeable.

[0404] Furthermore, the spatial relationship information identifier (ID) (TCI state ID) and spatial relationship information (TCI state) may be interchangeable. "Spatial relationship information (TCI state)" may be interchangeable with "set of spatial relationship information (TCI state)", "one or more pieces of spatial relationship information", etc. The TCI state and TCI may be interchangeable. The spatial relationship information and spatial relationship may be interchangeable.

[0405] In this disclosure, terms such as "base station (BS)," "radio base station," "fixed station," "NodeB," "eNB (eNodeB)," "gNB (gNodeB)," "access point," "transmission point (TP)," "reception point (RP)," "transmission / reception point (TRP)," "panel," "cell," "sector," "cell group," "carrier," "component carrier," etc. may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, picocell, etc.

[0406] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can be provided with communication service by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). The term "cell" or "sector" refers to a part or the entire coverage area of ​​a base station and / or base station subsystem that provides communication service within this coverage.

[0407] In the present disclosure, a base station transmitting information to a terminal may be interpreted as the base station instructing the terminal to control / operate based on the information.

[0408] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0409] A mobile station may also be referred to as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0410] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a wireless communication device, etc. Note that at least one of the base station and the mobile station may be a device mounted on a moving object, the moving object itself, etc.

[0411] The mobile body is a movable object that can move at any speed and naturally includes cases where the mobile body is stationary. Examples of the mobile body include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcars, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and objects mounted thereon. The mobile body may also be a mobile body that moves autonomously based on an operation command.

[0412] The mobile object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Note that at least one of the base station and the mobile station may also include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

[0413] 14 is a diagram showing an example of a vehicle according to an embodiment. Vehicle 40 includes a drive unit 41, a steering unit 42, an accelerator pedal 43, a brake pedal 44, a shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, an electronic control unit 49, various sensors (including a current sensor 50, an RPM sensor 51, an air pressure sensor 52, a vehicle speed sensor 53, an acceleration sensor 54, an accelerator pedal sensor 55, a brake pedal sensor 56, a shift lever sensor 57, and an object detection sensor 58), an information service unit 59, and a communication module 60.

[0414] The drive unit 41 is configured with at least one of an engine, a motor, and a hybrid of an engine and a motor, for example. The steering unit 42 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels 46 and the rear wheels 47 based on the operation of the steering wheel operated by the user.

[0415] The electronic control unit 49 is composed of a microprocessor 61, memory (ROM, RAM) 62, and a communication port (e.g., an input / output (IO) port) 63. Signals are input to the electronic control unit 49 from various sensors 50-58 provided in the vehicle. The electronic control unit 49 may also be called an Electronic Control Unit (ECU).

[0416] The signals from the various sensors 50-58 include a current signal from a current sensor 50 that senses the current of the motor, a rotation speed signal of the front wheels 46 / rear wheels 47 obtained by a rotation speed sensor 51, an air pressure signal of the front wheels 46 / rear wheels 47 obtained by an air pressure sensor 52, a vehicle speed signal obtained by a vehicle speed sensor 53, an acceleration signal obtained by an acceleration sensor 54, a depression amount signal of the accelerator pedal 43 obtained by an accelerator pedal sensor 55, a depression amount signal of the brake pedal 44 obtained by a brake pedal sensor 56, an operation signal of the shift lever 45 obtained by a shift lever sensor 57, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 58.

[0417] The information service unit 59 is composed of various devices, such as a car navigation system, an audio system, speakers, a display, a television, and a radio, for providing (outputting) various information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 59 uses information acquired from external devices via the communication module 60 or the like to provide various information / services (for example, multimedia information / multimedia services) to the occupants of the vehicle 40.

[0418] The information service unit 59 may include input devices (e.g., keyboards, mice, microphones, switches, buttons, sensors, touch panels, etc.) that accept input from the outside, and may also include output devices (e.g., displays, speakers, LED lamps, touch panels, etc.) that output to the outside.

[0419] The driving assistance system unit 64 is configured with various devices that provide functions for preventing accidents and reducing the driver's driving burden, such as millimeter-wave radar, Light Detection and Ranging (LiDAR), cameras, positioning locators (e.g., Global Navigation Satellite System (GNSS)), map information (e.g., High Definition (HD) maps, Autonomous Vehicle (AV) maps), gyro systems (e.g., Inertial Measurement Units (IMUs), Inertial Navigation Systems (INSs)), Artificial Intelligence (AI) chips, and AI processors, as well as one or more ECUs that control these devices. The driving assistance system unit 64 also transmits and receives various information via the communication module 60 to realize driving assistance functions or autonomous driving functions.

[0420] The communication module 60 can communicate with the microprocessor 61 and components of the vehicle 40 via the communication port 63. For example, the communication module 60 transmits and receives data (information) via the communication port 63 to and from the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, the microprocessor 61 and memory (ROM, RAM) 62 in the electronic control unit 49, and the various sensors 50-58, which are provided in the vehicle 40.

[0421] The communication module 60 is a communication device that can be controlled by the microprocessor 61 of the electronic control unit 49 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 60 may be located either inside or outside the electronic control unit 49. The external device may be, for example, the above-mentioned base station 10 or user terminal 20. Furthermore, the communication module 60 may be, for example, at least one of the above-mentioned base station 10 and user terminal 20 (or may function as at least one of the base station 10 and user terminal 20).

[0422] The communication module 60 may transmit at least one of signals from the above-mentioned various sensors 50-58 input to the electronic control unit 49, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 59 to an external device via wireless communication. The electronic control unit 49, the various sensors 50-58, the information service unit 59, etc. may be referred to as input units that accept input. For example, the PUSCH transmitted by the communication module 60 may include information based on the above-mentioned input.

[0423] The communication module 60 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from external devices and displays it on an information service unit 59 provided in the vehicle. The information service unit 59 may also be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH received by the communication module 60 (or data / information decoded from the PDSCH)).

[0424] Furthermore, the communication module 60 stores various information received from external devices in a memory 62 that can be used by the microprocessor 61. Based on the information stored in the memory 62, the microprocessor 61 may control the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, various sensors 50-58, and the like provided in the vehicle 40.

[0425] Furthermore, a base station in the present disclosure may be read as a user terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user terminals (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the user terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "sidelink"). For example, terms such as uplink channel and downlink channel may be read as sidelink channel.

[0426] Similarly, the user terminal in the present disclosure may be read as a base station, in which case the base station 10 may be configured to have the functions of the user terminal 20 described above.

[0427] In the present disclosure, an operation described as being performed by a base station may be performed by its upper node in some cases. It is apparent that in a network including one or more network nodes having a base station, various operations performed for communication with a terminal may be performed by the base station, one or more network nodes other than the base station (such as, but not limited to, a Mobility Management Entity (MME) and a Serving-Gateway (S-GW)), or a combination thereof.

[0428] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, the order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the specific order presented.

[0429] Each aspect / embodiment described in the present disclosure may be a technology other than Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG (x is, for example, an integer or decimal number)), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE The present invention may be applied to systems that use 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other appropriate wireless communication methods, or to next-generation systems that are expanded, modified, created, or defined based on these. It may also be applied to a combination of multiple systems (e.g., a combination of LTE or LTE-A and 5G).

[0430] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0431] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0432] The term "determining," as used in this disclosure, may encompass a wide variety of actions. For example, "determining" may be considered to be judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., looking up in a table, database, or another data structure), ascertaining, etc.

[0433] Additionally, "determining" may be considered to be "determining" receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), etc.

[0434] Furthermore, "determination" may be considered to be "determining" resolving, selecting, choosing, establishing, comparing, etc. In other words, "determination" may be considered to be "determining" some action. In the present disclosure, "determination" may be read interchangeably with the above-mentioned actions.

[0435] Furthermore, in this disclosure, "determine / determining" may be interchangeably read as "assume / assuming," "expect / expecting," "consider / considering," etc. Furthermore, in this disclosure, "does not expect to do..." may be interchangeably read as "assumes not to do...."

[0436] In the present disclosure, "expect" may be interchangeably read as "be expected." For example, "expect(s) ..." ("..." may be expressed, for example, as a that clause, a to-infinitive, etc.) may be interchangeably read as "be expected ...," "do ... (if the above "..." is a to-infinitive, a verb with "to")," etc. "does not expect ..." may be interchangeably read as "be not expected ...," "does not ... (if the above "..." is a to-infinitive, a verb with "to")," etc. Furthermore, "An apparatus A is not expected ..." may be interchangeably read as "an apparatus B other than apparatus A does not expect ... from apparatus A" (for example, if apparatus A is a UE, apparatus B may be a base station).

[0437] The "maximum transmit power" in this disclosure may mean the maximum value of transmit power, the nominal UE maximum transmit power, or the rated UE maximum transmit power.

[0438] As used in this disclosure, the terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access."

[0439] In this disclosure, when two elements are connected, they may be considered to be "connected" or "coupled" to one another using one or more wires, cables, printed electrical connections, etc., as well as using electromagnetic energy having wavelengths in the radio frequency range, microwave range, light (both visible and invisible) range, etc., as some non-limiting and non-exhaustive examples.

[0440] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0441] When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Furthermore, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0442] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0443] In the present disclosure, terms such as "less than or equal to," "less than," "greater than," "more than," "equal to," etc. may be interchangeable. Furthermore, in the present disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "fast," "slow," "wide," "narrow," etc. may be interchangeable, not limited to the positive, comparative, and superlative. Furthermore, in the present disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "fast," "slow," "wide," "narrow," etc. may be interchangeable, not limited to the positive, comparative, and superlative, as expressions with the prefix "i-th" (i is any integer) (for example, "highest" may be interchangeable as "i-th highest").

[0444] In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

[0445] In the present disclosure, terms such as "when A, B," "if A, (then) B," "B upon A," "B in response to A," "B based on A," "B during / while A," "B before A," "B at (the same time as) / on A," "B after A," "B since A," and "B until A" may be interchangeable. Note that A, B, and the like herein may be replaced with appropriate expressions, such as nouns, gerunds, and regular sentences, depending on the context. Note that the time difference between A and B may be nearly zero (immediately after or immediately before). A time offset may be applied to the time at which A occurs. For example, "A" may be interchangeable with "before / after the time offset at which A occurs." The time offset (eg, one or more symbols / slots) may be predefined or may be specified by the UE based on signaled information.

[0446] In the present disclosure, timing, time, duration, time instance, any time unit (e.g., slot, subslot, symbol, subframe), period, occasion, resource, etc. may be read interchangeably.

[0447] Although the invention according to the present disclosure has been described in detail above, it is clear to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The description of the present disclosure is for illustrative purposes only and does not impose any limiting meaning on the invention according to the present disclosure.

Claims

1. a receiver for receiving a cell switch command that triggers conditional L1 / L2 triggered mobility (CLTM); a control unit that controls the CLTM based on the cell switching command, The terminal, wherein the control unit acquires a timing advance (TA) for the target cell by a specific method before triggering the CLTM.

2. The terminal according to claim 1 , wherein the control unit acquires the TA by a method using a random access channel (RACH) or by terminal-based measurement.

3. The terminal according to claim 1 , wherein, when the TA is acquired using a random access channel (RACH), at least one of an early RACH resource and a RACH-based RACH resource is configured.

4. The terminal according to claim 1, wherein the control unit determines whether to perform RACH-less LTM or RACH-based LTM based on a specific condition when acquiring the TA using a random access channel (RACH).

5. receiving a cell switch command that triggers conditional L1 / L2 triggered mobility (CLTM); and controlling the CLTM based on the cell switching command; A wireless communication method for a terminal, in which the terminal acquires a timing advance (TA) for a target cell by a specific method before triggering the CLTM.

6. a transmitter for transmitting a cell switch command to trigger conditional L1 / L2 triggered mobility (CLTM); a control unit that controls the CLTM based on the cell switching command, The base station, wherein the control unit controls transmission of a setting regarding a specific method for a terminal to acquire a timing advance (TA) for a target cell before triggering the CLTM.

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